This fan-made patch for Serious Sam Classics includes a lot of modern enhancements that aren't present in the open-source release, nor in the official Steam patches since 2014.
This includes patches for the game, dedicated servers, tool applications and even gameplay logic. Despite this, it's perfectly compatible with vanilla The First Encounter and The Second Encounter servers and user-made content.
The goal of this project is to enhance user experience, as well as provide new ways of modding the games and, of course, play them.