https://github.com/openmultiplayer/open.mp
Also, server version 1.0 is out with minor fixes from RC1:
Server: Fix .so being required on Linux legacy plugins.
Server: reloadfs reuses its slot to preserve filterscript order.
Server: Attached objects are correctly shown to other players.
Server: Fix a crash when loading invalid pawn memory.
Pawn: Added GetPlayerMarkerForPlayer.
Pawn: Added a_??? file wrappers.
Upgrader: Supports multiple codepages.
Upgrader: Exclude files.
Upgrader: Full replacements report.
This is of course now at the updated download location of:
https://github.com/openmultiplayer/open.mp/releases
Also don't forget...
https://opencollective.com/openmultiplayer
https://www.patreon.com/open_mp