heavily-modified

There are 2 repositories under heavily-modified topic.

headcrab-junkyard/OGS
An open-source GoldSrc engine clone (Clean authentic reimplementation without using reverse-engineered code)
Language:C104 8 013
headcrab-junkyard/ApertureSrc
Further adventures of OGS Engine in Modernland (Alternative way of GoldSrc engine evolution)
Language:C9 3 02