Once installed, AppleJack is accessible from the Single-User Mode command prompt. (Hold down Apple-S while booting.) AppleJack can repair your startup volume, repair permissions, cleanup cache files, and validate preference files. It has a simple text menu so you don’t have to remember commands.

Also see the Macfixit article on AppleJack and read the cautions.

This could be a life saver in case of trouble.

Download:here

As you would expect, this is quite a useful tool.

I think that most Mac owners use Stuffit Expander for rar archives, but UnRarX has helped me when Stuffit Expander couldn’t do the job.

Next time you you can’t open up a rar archive, remember this post and come on back for UnRarX. (Or download it now and save yourself the trouble.)

Download:here

CLIX

Here is another UNIX utility, but this one is also for people that thought Terminal stuff wasn’t for them. CLIX (Command Line Interface for Mac OS X) is a GUI front end for UNIX commands. It comes with over 1000 commands so you can perform many tasks that are only available through the Terminal. For example, you can delete the browser history of all your browsers with just one command.

Advanced users can modify or write their own commands and save them as libraries of commands. Then just double click a task to run it.

Download:here

Do you have a wireless network and want to know who is connected? Do a ping scan on the whole subnet and find out if you have any visitors. Cannot connect to your MySQL database? Do a TCP SYN scan on port 3306 and see if the port is open.

This admittedly is not for everyone, but I use it regularly and you may find it useful too.

Download:here

Open Terminal Here

If you use Terminal and the UNIX command line often, this may come in handy. Open Terminal Here resides in the header of your Finder window, as seen below. When you click it, it opens a Terminal window for you and takes you directly to the location where you were working — helpful if you’ve navigated through your hard drive and then need to run a Terminal command there. This is a tiny app with a specific purpose from one of my favorite Mac developers.

Download:here

Mac OS X does periodic tasks to maintain itself. They are set to happen daily, weekly, and monthly. However, if you have your iBook or Powerbook asleep each night like I do, there is a good chance that these tasks have been missed. PseudoAnacron will help you be sure that Mac OS X performs these tasks.

PsuedoAnacron will be added as a login item. Each time your computer starts up, the program will check to see if there were any tasks that were missed, perform them, and then quit.

If you do not restart your computer often, you can also check out Anacron, which checks on startup and every hour. However, I prefer PseudoAnacron so I don’t have the service continuously running in the background.

SpoofMac lets you change (spoof) your Apple computer MAC address. This could be useful for network security testing. Also, I have been told that some schools throttle bandwidth by MAC address. This should enable you to get around that. (Don’t break any laws, but school rules are fun to break.)

This can also be done using Terminal, but SpoofMac makes it much easier.

Download:here

Platypus

Here’s one for the more tech-savvy user or developer:

Platypus creates a GUI app from a UNIX (Terminal) script. For instance, you may have an Applescript, Ruby, PHP, or Perl script that you occasionally run in Terminal. Platypus helps you put a “wrapper” around it so that it will run in the Dock, let you drag documents to it, and look like a regular app.

Download:here