Interesting URLs...

GNOME - http://www.gnome.org/
KDE - http://www.kde.org/

MICO (free GPLed CORBA) - http://www.mico.org/
TAO (free CORBA) - http://www.cs.wustl.edu/~schmidt/TAO.html

MySQL ("mostly free" database server) - http://www.tcx.se

XF (GUI builder for tcl/tk) - http://www.dfw.net/~mcody
SpecTCL (GUI builder for tcl/tk, Java..) - http://www.eolas.com/tcl/apps/SpecTcl/index.htm (was: http://sunscript.sun.com/products/spectcl.html)

C-Forge (IDE for C, C++, semi-commercial) -  http://www.codeforge.com

perl (free scripting language) - http://www.perl.com/
python (free OO scripting language) - http://www.python.org/
php3 (free web scripting language) - http://www.php3.net/