"Using AppleJack, you can repair your disk, repair permissions, validate the system's preference files, and get rid of possibly corrupted cache files. In most cases, these operations can help get your machine back on track. The important thing is that you don't need another startup disk with you. All you need to do is restart in Single User Mode (SUM), by holding down the command and s keys at startup, and then typing applejack, or applejack auto (which will run through all the tasks automatically), or applejack auto restart (which will also restart the computer automatically at the end of the process)"

Note: The developer originally mentioned that OS X 10.4 (Tiger) broke (hangs) permission repairs in Applejack but that other functions worked. See the readme in the download for the latest known issues, upgrade and usage instructions.

The latest version (as of 8/2013) is 1.6, released in July 2010.

Reader Reports: (most recent first)

(added 8/12/2013)
"Our iMac at Meals on Wheels of West L.A., running Leopard, suddenly "froze" in the sense that desktop icons could not be moved nor could files in folders; also whenever we tried to print anything we just got a message about a printing error; also, there were no services listed in any applications menu under the 'Services' item.
After running AppleJack all these problems disappeared and everything was right again. Thank you AppleJack!
- Ellen H., Director"

(added 8/19/2009)
" Ran Applejack yesterday on a MBPro 2.5GHz running 10.5.8 (had to fix a problem with Flash). (personally I'm not a fan of Flash and set the Flash settings manager (global privacy/security prefs) to not allow websites to store content on my HD, access the camera/mic, etc. Granted that has its drawbacks but I personally don't use flash heavy/required sites.) It ran fine using 'applejack AUTO' (deep clean) first, then going back and cleaning out the individual user caches and fixing user preferences afterwards. I'm guessing that this is as much scrubbing as this particular system can get from Applejack. No problems during the process, no problems since and the desired results were achieved.

Personally, I never run any programs regularly as maintenance, I only run them when problems (rarely) appear. I have fixed Macs for a living since System 7.1.1, and have found OSX to be robust over the years (well, that's put the kiss-of-death on that then...). I have found Applejack to be one of the primary tools I use when glitches appear, as I find that clearing caches can be a very useful procedure when the technology starts fighting back... YMMV as always! Open the pod bays doors Hal... I said open the pod bay doors Hal...
Cheers, Tim"

(added 8/17/2009)
" I have installed 10.5.8 on 10-15 Macs, and have had no problem. I usually run Applejack beforehand and restart twice, followed by running Onyx and rebooting twice. Then I run the MacOSX combo updater. Then I run Applejack and Onyx again. I may be a bit redundant, but I have never had any significant problem with updating, and I have been working on Macs for 20 years. (Ditto here (my first mac was the 128K model back in 1984), although I don't use AJ personally, I prefer the d/l updaters and generally have had no problems with updates (although I did see some of the common bugs in early leopard releases). And I don't go through the long before/after routines you do. I do reboot before installing updates (using DL updaters) as I rarely restart the main work machine and therefore like to do that to ensure as clean a ram/cache state as possible. And another important thing is to make sure you have a -current- backup before applying any OS update. (I have TM plus a clone of the boot drive.))

When I start Applejack, I run all 5 of the menu items numerical order. (Auto runs all routines automatically.) When I clean caches (menu item 3), I also clean each user account. When I run menu item 5, I tell it to delete the sleepimage file (if on a laptop). I restart twice because some items are repaired during the first restart process. Frequently, between restarts, I see the alert box that it is rebuilding boot caches.

I then run Onyx and select the Automation tab (looks like a hammer). I have all check boxes set on, so all I have to do is hit the execute button. When it finishes, it automatically restarts, and I then do a second restart (same reason as with Applejack). I have already set the preferences in Onyx to work on all user accounts and to restart after finishing. After rebooting, the Spotlight database has to be rebuilt. This causes mild slowdown until it is finished. This rebuild takes between 5 minutes and 2 hours, depending on processor speed and number of files on drive.

The only item that Applejack and Onyx do in common is repair permissions. If you prefer, you can skip it in Applejack.
(FYI - see my comments below about repairing permissions, common differences reported that you can ignore (and that won't be 'repaired' really - will show up again). I personally do not religiously RP if I'm not seeing any functional problems.) These 2 programs complement each other well, and keep the Unix underpinnings working better.
(AppleJack's original purpose was for cases where you had a drive that would not boot, allowing you to run the common routines/scripts for repairs/troubleshooting when you could not boot into the normal GUI/OS. I've never used Onyx personally so I can't comment on it but have used some other similar 3rd party utils, although I've been burned at least once by them. Although that mistake was quickly fixed by the developer, I don't religiously use these sorts of utilities for that reason and the fact my systems haven't really needed them.
I'm sure there's some rare exceptions (like corrupted files maybe), but I really don't see the general/routine need to clear/rebuild spotlight indexes and the hibernate file, except for cases where you're no longer using Hibernate mode (for instance as part of the previous tips for SSD drives here) or you're having a problem with laptop sleep/wake with Hibernate mode enabled.)

There are times when I don't want to take as long, so I skip Applejack and run Onyx only. Make sure you restart first so no other programs are running and memory is cleared out. Then, leave the Mac alone until this process finishes. Don't try to use it while it is being repaired.
David F.
Mac technician "

(added 8/17/2009)
" Power Mac G5 (6GB RAM) running OS X v.10.5.8,
5x500GB internal hard drives (three via SIIG-3114-R1 PCI SATA card)
AppleJack 1.5 works beautifully on my PowerPC-based machine. I ran it right before and right after upgrading to 10.5.8, and have had no problems. In fact, my machine seems particularly snappier, since the latter run.
I also have a 2.0-GHz white MacBook, but after reading the report below, I'm not sure I want to test that one. ;-)
Thanks, Jeff"

I wish I had $1 for every uncommon problem (with any update).

A first report from a 10.5.8 user (see above for later replies that didn't see any problems.)

(added 8/17/2009)
"I am running a Macbook Pro with 10.5.8 and Applejack version 1.5 revision 1.123, which was said on the SourceForge site to be Leopard compatible. (I don't use AppleJack personally but had one reader that used it w/10.5.7 on his Mac -before- updating to 10.5.8. However I've not gotten much feedback on AJ in the last year. Some may have installed it only for use if they had a problem booting from their HD. Personally I'm a bit leery of most 3rd party utils, especially any that don't seem that actively supported/updated. However IIRC all applejack does basically is call standard routines for RP, etc.)

I figured I needed some behind-the-scenes cleaning because I was experiencing a lag loading websites in Safari and also embedded video caused Safari to crash if I tried to launch another embedded movie after playing one. And hey, nice to have things clean. So I tried my maintenance utility that I downloaded whilst still using 10.4.11 and it reported it couldn't be run in 10.5. So after a bit of Internet I took the advice that Applejack was the best thing for it.

My results if I boot to single user mode and run 'applejack auto':
repair disks completes successfully after reporting ** FILE SYSTEM WAS MODIFIED **
repair permissions displays that it is starting minimal services and then gives some errors followed by pages worth of faults that seem to centre mostly on QuickTime stuff. Reports are for 'permissions differ' and that some files have been modified and will not be repaired.
(FYI: There's a long list of permission 'differences' seen in Disk Utility that are normal/can be ignored and won't really be repaired. (Including a -long- list of "coderesources" differences listed (and not just QT related) for some time now.) I mentioned these on the 10.5.8 feedback page here but have seen the same things for quite a while (before 10.5.8). Here's the Apple doc with a (long) list of OS X 10.5: Disk Utility Repair Disk Permissions messages that you can safely ignore (TS1448 no longer online). And some users of the "Combo" 10.5.8 update have reported "blank" permissions ("should be ?---------") and suggested reinstalling the Combo update a 2nd time. Personally I'm not rabid about running repair permissions.)
cleanup cache files seems to be fine
validate preference files seems to be fine
clean up virtual memory seems to be fine

The end result is that I am NOT ABLE to boot to OS X. When I press the power on button, the laptop displays the Apple logo, then the timer ring, and then the screen greys out and I'm left with a message saying that I need to restart my computer.
Absolutely catastrophic for me at this point in my schedule.
Regards, Cluesome."

I asked if he could boot from a 10.5 Disc (or other bootable Ext. drive) and try repairing the boot HD (not repair permissions, repair disk) and/or try reinstalling the 10.5.8 update from a download.

(Older reports from 2008 and earlier follow)

(added 9/3/2008)
"Just installed and ran AppleJack v1.5 on my MacPro everything went smooth as silk...
No double restarts or weird permission repair behavior and the fans stayed quiet throughout the whole process.
(I've not yet owned a Mac Pro so I asked if the fans spun up when running Apple Hardware Test (as they do with my PPC G5 Tower).)
Just ran Hardware test and nope the the fans were quiet.
Mac Pro Quad 2.8GHz /250GB X 3 / 500GB X 1 / 5GB Ram /Dual 16X SuperDrives/ Leopard 10.5.4.
Regards, Robert B."

(added 9/2/2008)
"AppleJack 1.5 works fine on my Sawtooth G4 with 10.4.11. I expected this would be the case but it is nice to confirm it still works with the "old" OS. :)
-Ronald P."

(added 9/2/2008)
"Until I installed OSX 10.5 - currently 10.5.4 on a G4 Quicksilver 933MHz and a PB G4 (AL) 1GHz, I ran Applejack 1.42 on both machines on a monthly basis and never had a problem. After installing 10.5 on the QS machine, I continued the monthly maintenance schedule using Onyx. Onyx offers more features but is not as easy to use as AppleJack. (Applejack's main benefit was it could be used when a problem prevented being able to boot into OS X normally to run other repair software and/or when you didn't have other repair/utility discs handy.)

With the release of AppleJack v1.5, I installed and ran it on the QS machine and experienced no problems. After running AJ 1.5, the machine is perceptibly faster and more responsive. I expect the PB run will be similar.

I also support a friend's G5 iMac (2005 model) running OSX 10.4.11. When running AJack v.1.42 there, the fan does run continuously and sounds like a hair dryer going full tilt. The fan stops upon reboot.
-Sanford"

I suspect just as I see with a G5 tower when running the AHT (Apple hardware test boot) disc, without the fan control software running the fans default to "failsafe" mode (i.e. full blast).

(added 9/2/2008)
"Long time since I used AppleJack...v1.4x caused me nothing but problems with my SeriTek RAID (bootable 2TB volume that runs my G5 Dual Core 2.3Ghz PPC Mac), so when I saw the article about v1.5 on your pages yesterday, I had to try it out, if nothing else to see if it would now work on the damn machine! (I'm using Leopard 10.5.4 with all updates.)

So I installed it, printing out the Read Me, and I see the command lines haven't changed anyway, so hit "applejack AUTO restart" and let her fly.

A most amusing 24 minutes of AppleJack insanity, fans blowing at full tilt boogie ensued (no fan control software running so fans run in "failsafe" mode (full blast)), but the end result was the G5 booted TWICE (scared me for a minute!), because it landed on its feed booting into the RAID (the volume that I installed it on), and it seems like everything is aok fine so far.

There was some heavy-duty Permissions Repair, as in almost 15 minutes straight of it, with a couple thousand line item reports (!), lots of "ACL Found But Not Expected" warnings in the reports (deja-vu, seen early on with Leopard running RP from Disk Utility (noted last winter here in the news page/Leopard feedback page), although I've not seen that after later leopard updates.), but when the caches were cleaned, and the VM and swap files done up, I knew that the developer had done his work right.

If it will work on this SeriTek RAID box, it will work on ANY G5 or Intel Mac setup, IMO. Congratulations to the man who writes this great, but scary program :-)!!

I haven't had my G5's fans blow at full tilt boogie like that in a couple years, LOL! Cleaned out some of the parrot dust therein, I'm certain.
Kindest Regards, David C."

FYI: reports below are before v1.5 was released (w/OS X 10.5 compat.)

(added 2/20/2007)
" We've found Applejack to be both convenient and it seems to do a good job. But, coincidence or not, since installing it on 11 systems running 10.3.9 in a production (graphics) environment in early December and another 7 macs running 10.4.6-.8 in a systems engineering environment, all of the monitors are going to black for a few seconds at a time at random times while the mac is in use. (not from display sleep/idle time I assume. Could a display or energy saver prefs file have gotten corrupted?) This started the day after we installed Applejack and it only stopped on two of the systems when we restored from a recovery image that did not include an install of Applejack, one running 10.3.9, the other 10.4.8. (what version of Applejack was used?)

This has included everything from 1.25GHz eMacs to quad-core PPC G5s and even a few Intel Mac-Minis and one Mac Pro quad-core. It has also happened to mirrored door G4s and on PPC PowerBook 17", next to last generation.
Any thoughts on this, anyone else seen this? We're baffled and hate to lose the efficiency and convenience of applejack. Typically we do an applejack AUTO shutdown (or restart) when using it.

(I don't remember anyone else seeing this in the past, but I sent Keith a couple questions. (Did the blackouts start happening after Applejack was installed or only after it was used for disk repair or maintenance? Have you tried creating a test user acct on an affected system and then log in under the new user acct to see if the display blackout still happens?)
No (AJ had been run on all) and yes, respectively, on these issues.

(I asked again for the applejack version used (in case later versions had problems not seen by readers using older versions))
Same for all, v1.4.3. I never installed any previous version and all installs were made with all 3rd-party processes disabled (not Safe Mode, but a manual disabling of these processes that traditionally interfere with installs, like HP's myriad print processes their installers are notorious for, and daemons like MS Office's mail daemon).

About 2/3 of the machines have LCD monitors, off the DVI port, the rest CRT. There's no difference between the frequency of occurrence between the LCD and CRT units.

Yesterday I used a restore image that did not have AppleJack installed, restored it to my own G5 and I've had no incident since restoring the image w/out Applejack. Something's going on, but I'm not ready, yet, to blame AppleJack. Because some of Apple's security patches can cause the same problems (blacking out of the display), many people may be seeing this and accepting it as the fall-out from installing the Security patch rather than associate it with AppleJack. Other Apple OEM patches, when applied via the Software Update function, can cause identical or similar problems.

We, however, NEVER install Apple's security patches as of last year since we picked up on a serial pattern of problems with how they're put together and run onto the machines. We also don't use Software Update but download all patches, upgrades as full, desktop installs, made in the Safe Mode or w/disabled 3rd-party processes, whatever's appropriate for the particular update, patch, etc.

These machines are clean, run very well, and this is the first systemic problem we've encountered since the fall of 2003. Hope it isn't AppleJack as I like the convenience.
-Keith "

" I currently have Applejack installed on six Macs; late 2005 Dual 2.3GHz G5 (10.4.8), two dual 1.42GHz MDD G4s (one FW400, one FW800, both on 10.4.8), one AGP G4 w/1.5GHz OWC upgrade (10.3.9), one 800MHz Powerbook G4 (the one I bought from you a couple years ago - running 10.3.9), and one 1.5GHz G4 Mac Mini (10.4.8). Not one of the machines is experiencing the problem mentioned.
(I asked what version of AJ was used - he later replied v1.4.3)
I have a varied range of software installed on each machine (you name it - games, multimedia authoring, page layout, illustration, image editing, DV production, general productivity, etc.), so I honestly donít know what advice to offer other than my comments on not having experienced the problem.
-Leo "

Another reader said he's seen the same thing and had never installed AppleJack:

" I have seen this problem until recently too and I don't have Applejack installed. It happened just as the reader describes, at random, from time to time while typing for example or surfing the net. So it is clearly not an issue with the evergy saving preference pane. (I had asked the person that originally saw this if a display or ES prefs file could have gotten corrupted. this is why I asked if he'd try creating a new user/login as the new user acct to see if a fresh set to user settings/prefs (and no user added login items/addons, haxies, etc.) would make a difference.)

I had the problem only on my G5 1.8 Mhz with the stock GeForce 5200 card. Never had this problem on the eMac or on the Macbook core duo. I attributed the problem at the time to my new Buffalo LCD monitor connected with a DVI cable. (I asked why he thought that - suspected the DVI cable or monitor? (i.e. was it not seen until he started using that monitor?)
The screen went dark sometimes as described for 1-2 sec and as soon as I moved the mouse everything reappeared. (as if the mouse movement turned on/woke up the display. I have my PB set to turn off the display after 1 min of inactivity (to save the backlight), but those seeing this had it happen during continious use they said.)

I recently changed that GeForce 5200 for an ATI Radeon 9800 and moved the startup disk to a new 500GB internal Maxtor drive with Superduper and the problem disappeared. His "fleet" of macs though seems quite different in nature and the problem may have nothing to do with the videocard.
I am running now OS X 10.4.8 fyi.
-Frank "

With the wide range of macs he mentioned, there are too many different graphics cards/onboard graphics for the problem to be related to one specifically.

(added 11/7/2006)
"I've been using Applejack 1.4.3 rc3 on two Intel Macs over the last few days running 10.4.7. So far so good. It correctly fixed a problem I was experiencing with a hang at startup with a MacBook Pro (Core Duo 2.0ghz). On a Mac Pro (2.66ghz) it cleared up some cache related problems that were crashing a few apps.

I'm very pleased that it's back as it's usually the first thing I try when troubleshooting.
-Shawn"

NOTE: Reports below were before v1.4.3rc3 was released

(Oct. 11th, 2006 mail)" After diagnostics by Applejack, my I-Mac (Intel iMac or PPC iMac??) fan runs at top speed sounding like a jet engine. How do I revert to normal speed? Tiger 10.4.8.
-Art "

Fans still run at full speed after a normal boot/reboot? Did you try resetting PMU? There's now a update to AppleJack that's intel mac compatible. (See above)

(Oct. 5th, 2006 mail)
" let me start by express my thanks for the nice utility.
I had an installation of Tiger on a 2.5" external drive, which I moved to a more performant 3.5" FW800 hard drive. I used Disk Utility for this task, but although it worked seamlessly, it seems that didn't completely succeeded with permissions: actually i couldn't serialize any application for permissions-related problems.
So I ran Applejack and it fixed!
In the mean time, I ran it on a G5 Dual Processor and while the persmission were repaired, the fans spun louder and louder until I tought my G5 could take-off!
So my suggestion is: please start the temperature-controller deamon as well as soon as the Applejack script starts.
Thanks again
Paolo "

(from May 19th, 2006 mail)
"I am running 10.4.4 on a brand new iMac Intel 2 gig 20 inch system -- I downloaded Applejack 1.4.2 and installed it over 1.4.1---I have used Applejack successfully for 2 years now on my G4 desktop tower running 10.4.6. (Note - see earlier reports on Intel Mac issues with AppleJack 1.4.2 and before, I'd not run it on an Intel Mac until an update that's compatible is released. (Note: On Nov. 7th a 1.4.3rc3 release was done that says it's intel compatible.)) Today I tried running Applejack 1.4.2 on the Intel using "applejack auto restart" and it hangs in middle of Task 3with following "exited abnormally:bad system call hank humphrey's computer: I have no name!# SIOCPROTOATTACH_ING: en0 error=17"
can anybody help me get it to run thru??
-Hank "

(March 19th, 2006 mail)
" i've been using applejack since version 1.2.x (during the jaguar days). when repairpermissions broke with panther (since systemservices needed to be launched in single user mode), i contacted the author and got a few of the guys at the xserver admin list to help. before long version 1.3 was out (worked around the repairpermissions problem).

applejack is the right tool for the job when you have hundreds of users running around the globe who may need help if they can't boot from their emergency disk. booting into single user mode and running specific options (or the whole thing using the "auto" function) is simple and extremely effective.

the sysadmins at the xserver list are throwing a hissy fit over applejack. why? because it simplifies many of the unix commands that a remote user may need to run. two admins on the list (no names) are extremely upset that applejack exists. many other sysadmins have emailed me offlist to praise it's existence. call it a severe case of job security. :)

apple really needs to pay this kid to be on their payroll. bombich got to apple the same way - create an indespensible tool/method (something that EVERY sysadmin admits they can't live without), and have apple bring them onboard.

the applejack developer is extremely bright, proactive and deserves to be on apple's payroll. applejack is picking up serious steam and rightfully so. it's an excellent, well thought out tool. it's on all my builds (updates get pushed out when they've been tested)...wouldn't have it any other way.
-Don "

Donations for Intel CPU Mac Mini for Applejack Developer (NOTE - the donations are complete - Intel CPU Mac was purchased so this post was removed)

First Intel CPU Mac/AppleJack 1.4.2 report: (Update - see above for later update that's Intel CPU Mac compatible.)

(added 3/30/2006)
"AppleJack 1.4.2 is broken on all Intel Macs.
The process completes disk repair without issue, but will hang on permissions repair, offering an error message that the computer cannot find it's name.

I had to force a reboot. Thereafter, some Finder Menu items fail to load during startup. Apple Remote Desktop will not load properly.
-Mark M. "

(Note - the developer previously mentioned when Tiger was released that it broke the permissions repair in Applejack (hangs), but that all other functions appeared to be fine on PPC Macs at least.) I sent an email to Kristofer (the AppleJack developer) about this and he replied:

" Yes, unfortunately it appears that the subsystem tools that AppleJack hooks into to perform its tasks are either incompatible with the flags I'm throwing them from bash, or they are simply not as robust on the Intel platform as they are on Power PC.

I have a hard time believing it's a problem with the Intel version of zsh (the default single user mode environment), or with bash (the shell language AppleJack is written in).

I will try to take some time this weekend to post this to the AppleJack sites.

As it looks, since there is no information from Apple on how to work with or program anything in single user mode, I am strongly considering just stopping development of AppleJack. With every version of Mac OS X something becomes less stable or predictable, and there is, as I said, absolutely no documentation from Apple on how to use the tools they provide in single user mode. I think they'd rather people just stay away, and to this overworked developer, its working.

If there are people out there with the skill set and patience to develop AppleJack further, I would like to speak with them. At the moment I have no Intel Mac to test it on (I only own one macintosh, and that's an old iBook g4).
-K. "

(added 2/28/2006)
"I also has been using Applejack for awhile now.
It runs very well on all the Macs that I have installed except for one 17" 1.5Ghz Powerbook.
The repair permissions step takes forever.
I think it started since the earlier version of Tiger and at 10.4.5, it still exhibits the issue. (the developer noted in spring 2005 that PR via Applejack hangs in Tiger)
Recently I did a test by repairing the permissions in the Disk Utilities prior to running it under Applejack.
Disk Utilities only took a few minutes and Applejack took more than 2 hours right after the first test.

One other feature that I think will be helpful is for Applejack to generate a log file so that when running auto-restart, one can go back and read what's been fixed.
-Ray "

The developer posted a note when Tiger was released that it broke the permissions repair in Applejack (it hangs), but all other functions of AppleJack appeared to be fine.

(added 2/27/2006)
"No problems using AppleJack on my 1.67GHz 15" PowerBook G4 running 10.4.5. Skipped resetting the preferences as suggested and was done in say 10 minutes.

My G3 iMac running 10.3.9 though got hung up endlessly (+3 hours) on the permissions step (I asked if he had updated that system with iTunes 6.0.2 - which had the permissions repair problem mentioned in the main news page back then (See Fix for Can't Repair Permissions problem in 10.3.9) Not sure if iTunes 6.0.3 fixed that as I already had applied the 'fix'.) and I finally had to execute a control-Z to interrupt the program. There's another earlier post with the same results on an iMac; and although that author attributed it to the OS version, perhaps it has more to do with running this program on an iMac.
-Bill"

(added 11/10/2005)
"Using AppleJack last night I repaired something that DiskUtility and Diskwarrior missed.
http://www.shirt-pocket.com/forums/showthread.php?t=318
(above is forum thread on SuperDuper permissions problem with 10.4.3)
I couldn't back up my drive until I updated AppleJack for Tiger and ran it. Then it worked! Bless AppleJack.
OS 10.4.3, AppleJack 1.4.1 update
-Bruce T."

(added 5/16/2005)
"Tried Applejack on our eMacs at school and it works fine. As the Tech coordinator with 102 units to manage, I think Appplejack is going to be a really hand ap for me.

A friend got a new iMac G5 Thursday with the wireless keyboard and mouse. I loaded Applejack and then started in single user mode only to realize that it was NOT going to work because the wireless functions do not operate in Single user mode--therefore cannot use the command line for input. I believe it's worth listing in the requirements that wired keyboard connection is necessary. Did not see any mention of this problem on the feedback page.
-Rick"

Personally if I had a wireless keyboard setup I'd still keep a USB (wired) keyboard around just in case.

First report on Applejack v1.4.0 w/Tiger:

(added 5/9/2005)
"I had reason to "test" applejack 1.4 with Tiger this weekend & it appears to have passed with flying colours.

Let me explain. I'd been playing Doom 3 since about 11:30 Saturday night and time was getting on, so I quit the game to return to the desktop. All functions, from launching apps to opening windows, had become extremely sluggish and a reboot didn't help. With hindsight, I should have realised that, at 3:40 in the morning, the Cron jobs were running but it had been a long day and that shouldn't have crippled my mac to the extent that I was seeing.
I'd installed applejack earlier so I booted into single user mode. About 3 different error messages regarding USB were repeating but I managed to run applejack. It ran slowly, found quite a lot of stuff to repair and rebooted back to a normal system.
To be on the safe side, I ran it again and this time it zipped through its routines and reported a clean bill of health.
I've had no issues since and, although that's only been a couple of days, I feel that disaster has been averted.
Regards, Calvin "

(Note - reports below were before v1.4 with tiger compat. was released)

(added 5/1/2005)
" I installed and ran Applejack 1.3.2 on my new installation of Tiger 10.4 on an iMac G4 1.25Ghz. Applejack loads and runs but when it gets to Repairing Disk Permissions, it goes on indefinitely (essentially forever). Apparently something is broken in Applejack under Tiger, but I don't know what.
Erik S."

(added 4/26/2005)
"applejack (v1.3.2 I assume) doesn't work with OS 10.4
-Lieven "

(added 3/2/2005)
"I've used Applejack and it seems to be just a series of scripts for some low-level repair... Nothing you couldn't do with terminal commands (in single-user mode), but much more convenient. The install size is small and it doesn't do anything until you tell it to - hard to find a downside.
If memory recalls, it does the following:

FSCK disk check

repair permissions

verify preference files

remove cache files
(Yes, the AppleJack main page (and past reports here) notes that but still very handy (avoids typing/remembering all the command lines).)

Just wanted to add - I put it on a master image that we've deployed to 1200 laptops scattered over about a 100km radius - when I have users call in with problems it's a lot easier to walk them through this than to make them go through all the terminal commands... of course, I usually just get them to boot holding the shift key as that runs an FSCK and often fixes the little glitches and is very non-techy...
-Jeff D. "

Booting with shift key (sort of like "safe mode" in windows) automatically runs FSCK on the boot disk but some problems can be related to corrupt prefs files also - one common tip/test for that (if the system can still boot into the OS of course) is to create a user acct and login as that new user (to test if problems are due to correct preference file). The FAQ's OS X section here also links to an Apple kbase doc on Troubleshooting OS X startup problems.
I know I used to create tons of batch files when all we had to use was DOS at work. Saved a lot of typing (and potential mistakes/typos). As mean readers have mentioned, I also hope apple incorporates something similar into a future os. (All those popular GUI utils also generally just call built in routines.)

(added 3/2/2005)
"Applejack works great for it's primary purpose, which i assume is checking on local accounts, however, it would be nice if you could map out to LDAP accounts and check them. I work for a large company that uses LDAP exclusively for user accounts (about 1500 of them). so it would be very nice to check on there home folder items without having to boot the home directory server into single user mode.

other than that, applejack works great!! it's nice to know i have an option to do some troubleshooting if the machine bombs and i don't have an external to boot from.
thanks, Mark K."

(added 3/2/2005)
"Awesome! Works better than advertised! This definitely needs to become implemented into the OS. Apple are you listening?! We've needed this functionality for so long it's not funny!
For those with 3rd party drives that won't boot a start up disk it's your lucky day. No more swapping drives around just to run a boot disk. Hurrah! Finally!
I too am a complete command line / terminal idiot. Follow the simple directions, this could not have been made easier! 5 apples. Forgot the best part ... IT'S FREE! Well, you could donate though.
-Tk"

(added 3/1/2005)
"Seems fine except I ran just 'applejack' and you do NOT want to walk away! (many just use "applejack auto restart" command/)

I was watching the prompts and the repair process when someone called me away from my desk. 15 minutes later I walk back into my office and hear this noise; the G5 fans were at FULL after the process was completed. (since in the command line there's no fan control running just as with the hardware test CD - the fans ramp up to full speed (fail-safe mode)) I definitely recommend the 'applejack auto restart' command instead. (papers on the divider where flapping like flags!)

So far, I wish Apple had this builtin...(I know most of it is..but the convenience). Nice app.
-Ed "

(added 3/1/2005)
"Very handy when you need it. I've installed it on both my work computers. I hope Apple considers implimenting something similar in a future OS.
-Jesse "

Contrary to want one reader said, this user reported it worked fine on his RAID array:

(added 2/28/2005)
"I would like to add to my comments on Applejack. I have 2 Maxtor HDs striped via a SIIG (aka Acard) ATA133 RAID card. I have been using the RAID array as my system disk for about 18 months and Applejack works fine with this arrangement. I keep my whole system on this volume. I can't say how well Applejack works if Home folders or what have you are moved to different disks - lots of other stuff breaks so I wouldn't be surprised if Applejack couldn't deal with it either.
Ronald P."

(added 2/28/2005)
"I saw your call for feedback on AppleJack. I'm a Mac consultant and started installing it on all the machines I work on. I tested it for a couple of weeks on my own machine and it has proved to be a solid program that has already fixed a couple of problematic Macs. As far as I'm concerned, it's indispensable.
-Brad B. "

(added 2/28/2005)
"I've been using Applejack since it became available and it has been invaluable and bug/glitch free. Usefully, when running Repair Permissions it will display specific information not provided by either Disk Utility or Disk Warrior. Thus in my case, whereas Disk Utility ran a Repair Permissions as if all was well with the drive, Applejack listed 579 iNode faults which are not repairable. Disk Warrior confirmed this potential problem (iNodes severed from original files) but did not list them.
All the best, Gavin "

(added 2/28/2005)
"I use applejack regularly instead of other programs like disk utility, macjanitor, or cocktail. It is a terrific, easy to use program.
-Sam "

(added 2/28/2005)
"Applejack + DiskWarrior = Best OSX repair kit available.
-Michael V. "

(added 2/28/2005)
"I have a G4 DP450 / 1GB ram /2 x 80 GB Internal drives/ and a 30GB and a 40GB on a Ultratek 66 IDE card and external 160GB Firewire drive/ Hammerfall MultiFace Audio interface / Pioneer A107D DVD.
I tried the AppleJack utility and sofar everything seems to have gotten snappier, opening and closing windows, launching apps etc ... Sorry I don't have tests before and after to verify. The utility was very easy to use as long as you are comfortable in the single user mode ( command + S ) during the start-up.
Regards, Rob B. "

(added 2/28/2005)
"Use it to run repairs on my system once a month (whether it needs it or not). Updated to the latest version of it as of today and the program is the best and speediest solution I've seen to date. No issues.
Mark "

(added 2/28/2005)
"I LOVE applejack.
i have had a few KPs in the past month. when i rebooted out of one all i had to do was boot into single user mode and type applejack, hit enter, and then type the A key and hit enter. applejack then repairs the disk, repairs permissions, cleans cache and looks for bad prefs, its really neat and on the occasion your mac crashes, its invaluable!!!
-KM "

(added 2/28/2005)
"I have used AppleJack on two G4s and a dual G5 and it has been great. Just started using it about a month ago, but I have installed it on other clients' Macs to use in an emergency phone situation, talking them through booting into single-user mode and then using the "applejack auto reboot" command. This is, however, risky with some clients...
-Mark "

(added 2/28/2005)
"Applejack is fantastic! I manage about 20 Mac computers. Whenever I start to have problems on any, I run Applejack. It basically makes it possible to repair your disk, your permissions, clean your caches, and check your preferences for corrupt files in one go.
Jim W. "

(added 2/28/2005)
"I've been using AppleJack for a year or so now, and I adore it. It doesn't do anything that can't be done with a series of terminal commands, but it does it all as a single shell script. It's easy enough to look at the thing's script and determine what it does, and you can also limit what repairs it will do when invoked (via a simple numeric prompt).
But, basically, the coup de grace is the "autopilot" function which will fsck your drive, repair permissions and clear up your cache files. Very nice, very easy. Great way to repair a drive in one step, especially if you aren't able to boot into more than single user mode.
-Nik "

(added 2/28/2005)
"This utility is absolutely fabulous. It's saved my butt quite a few times. Even when the GUI won't boot, you can still use AppleJack. Just start up in single users mode, type in "applejack" and do the whole suite: verify and repair disks, repair permissions and clear caches.
It works as advertised. It does more than Apple's Disk Utility and that all without rebooting from a CD or an External Firewire disk. This one comes highly recommended and it's something Apple should build into their OS. Tiger maybe?
Thanks for a great site and keep up the excellent work for the Mac community! Best regards, Daniel "

(added 2/28/2005)
"I have used Applejack and it's really handy, faster than booting off a CD or second volume to repair the disk. And, you can run ALL the other CHRON tasks at the same time instead on booting Onyx or Cocktail etc. Kinda kills a few birds with that one stone.

The drag with it however is that it can't work on a RAID array.
(Note - a reader above reported it worked fine on his PCI IDE Card RAID array.)
...Cheers! -"Macaholic" "

(added 2/28/2005)
"I use AppleJack and I am quite pleased with it. That said, it is not for everyone; AppleJack is a command line tool and works in single user mode.
However, if your Mac is borked badly AppleJack can save your bacon. Installation is easy and usage can be as simple as typing "applejack auto reboot" and letting do its thing.
Ronald P. "