well it isn't just get the C code compiled in a C++ compiler but fully object-oriented
http://code.google.com/p/cleancodequake2/
This seems rather new (SVN r1 is dated Mar 2009) and SVN is still being updated. Some of the code syntaxes actually remind me a lot the HL syntax, such as class names like "CBaseEntity" or something like this:
Code:
LINK_ITEM_TO_CLASS (item_armor_jacket, CArmorEntity);
LINK_ITEM_TO_CLASS (item_armor_combat, CArmorEntity);
LINK_ITEM_TO_CLASS (item_armor_body, CArmorEntity);
LINK_ITEM_TO_CLASS (item_armor_shard, CArmorEntity);
haven't take a deeper look yet though