Zoner's Half-Life compile tools offer many improvements over the original
map compiling tools for Half-Life, such as better lighting quality, faster
vis times, switchable texture based lighting, support for brush entities
casting shadows, removal of "sticky" edges, support for 64-bit processors,
and much more.

Please note that these tools are for use with the Half-Life 1 engine (also
known as GoldSrc or GoldSource), not for the Source Engine used in Half-
Life 2.  For the Source Engine, refer to Custom Source Tools (CST).