Custom Textures
3Ds Max 8
http://files.h2vista.net/software/3dsmax/
(HEK) Halo Editing Kit for Halo CE
http://hce.halomaps.org/index.cfm?fid=411
Halo Custom Edition Game [English]
http://hce.halomaps.org/index.cfm?fid=410
Tool++
http://hce.halomaps.org/index.cfm?fid=578
Gimp