Q2PRO is a Quake II engine modification.  Client and server sides are both
compatible with original Quake2 v3.20 network architecture, as well as with
modern R1Q2 network architecture.  Q2PRO is designed to be secure, fast, and
doesn't provide any graphical enhancements that are contrary to the classic
Quake2 look and feel.  It yet provides some features unique to Quake2, most
notably server side MVDs (multi view demos).  Q2PRO has its own software and
OpenGL refresh libraries and runs under Windows and Unix-like systems.

Q2PRO supports the following network protocols:

  - 34, original Quake2 protocol
  - 35, enhanced R1Q2 protocol
  - 36, enhanced Q2PRO protocol, extension of R1Q2 protocol
  - 37, special broadband MVD protocol

WWW: http://q2pro.sourceforge.net/