Powertweak-Linux is a tool to tune your system to its optimal performance settings. It started life as the replacement for the now obsolete kernel option 'tune PCI bridges', and has been extended to provide more features and support more chipsets. It can also tune network/filesystem performance using /proc/sys entries, disk elevator settings, and x86 CPU registers (needs 2.2.18 or 2.4.0test kernel), CDROM speeds, hdparm type features, and Sony VAIO backlight. It has both a GTK GUI and a text-based lister.
CYCAS is a 2D+3D CAD package for drafting and design in high quality and for creating 3D presentations and technical illustrations easily. Some of its features include an easy-to-handle user interface, special architectural elements and functions, a WYSIWYG display, printing, plotting, import and export filters, photorealistic rendering with POV-Ray, documentation and tutorials, example drawings, and an extendable 2D/3D symbols library.
The Linux-Ecology-HOWTO discusses ways to make computers less harmful to our environment and to solve some ecological issues. It explains how to use Linux to save power and consumables like paper and ink. Since it does not require big hardware, Linux may be used with old computers to make their life cycle longer. Games may be used in environmental education and software is available to simulate ecological processes.