Valve Hammer Editor 3.5.2
The Valve Hammer Editor 3.5.2 is the last unofficial mapping tool for the Goldsource engine (Half-Life 1 and his mods) based on the last beta 3.5 made by Valve.
See the readme file for the full changelog below:
Valve_Hammer_Editor_3.5.2_Setup.exe****Update 11/30/12: Update compilers tools Vluzacn 30.
Screenshot of the interface.