The source code from mineplex 2018 leak with commit history dating back to 2014, it requires a lengthy setup to get functional but is a reasonably easy compile if you know what your doing just have to repatch the spigot

Chiss 35c10f22a1 Fixed gems in a few games ... Milk Cow; cannot pickup water, cannot drink milk after end		2013-09-14 08:13:21 +10:00
Maps	Bob wants to play!	2013-08-29 15:55:49 +10:00
Plugins	Fixed gems in a few games	2013-09-14 08:13:21 +10:00
TestApps/LOCTester	Initial Commit	2013-08-27 08:14:08 -07:00
TexturePack	Initial Commit	2013-08-27 08:14:08 -07:00
Webserver/ServerHandler	Initial Commit	2013-08-27 08:14:08 -07:00
Website	Added in dynamic servermanager updating.	2013-09-11 13:53:24 -07:00