Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
There aren't a ton of system tweakers for Linux, but we have to give a shout out to the very useful Ubuntu Tweak. It can change tons of extra settings in Ubuntu, make applications easy to install for beginners, and clean up unnecessary files on your system.
* View basic system information about your distribution, kernel, CPU, memory, and more
* Tweak the session menu and the way Ubuntu handles logout, restart, and shutdown
* Choose programs to auto-start at boot
* Quick install popular applications, including those not in the Ubuntu Software Center (and easily add new repositories)
* Clean up unneeded packages or cache to free disk space