Currently, the only things available here are Quake 1 related.

Enhanced versions of Tx/TreeQBSP, support for any Quake 1 editor including QuArK, Hammer and GtkRadiant
      Here it is : txqbspbjp.zip    (Version 1.13 Oct 2006)     Changes from 0.6 : readmetx.txt
      Here it is : treeqbspbjp.zip     (Version 2.05 Apr 2007)     Changes from 1.62 : readmetree.txt

Enhanced versions of RVis, Light & BspInfo
      Here it is : visbjp.zip    (Versions 2.31/1.43/1.27 May 2006)     Changes : readmevis.txt

Enhanced versions of Win/GLQuake for mappers and Nehahra engine
      Here it is : glquakebjp.zip    (Version 1.33 Aug 2007)     Changes : readmegl.txt
      Here it is : nehquakebjp.zip    (Version 3.08 Aug 2007)     Changes : readmeneh.txt

Tools for Quake 1 wads/maps/demos
      Here it is : dupwad.zip    (Version 1.00 Mar 2004)     Changes : readmedup.txt
      Here it is : convmap.zip    (Version 1.9 Sep 2004)     Changes : readmecnv.txt
      Here it is : convdem.zip    (Version 1.4 May 2007)     Changes : readmedem.txt

Useful links for the hardcore Quake player:

TEAMShambler	THE Quake 1 SP review site archive	::LvL	Q3A review site	Q1 ToolTips	Quake 1 level design tips (v0.19 Jan 2007)
Ten Four	Quake 1/2 (+ others) SP review site	Rust	Level design	QMap Mapping Help	Old level design thread
Ethereal Hell	Quake 1/2/3 (+ others) review site	Func_Msgboard	Quake level design
Underworldfan	Quake 1 & Cube SP review site