Open5Gs
Formerly NextEPC.
OpenAI Core Network
Related to / branched from OMEC.
Magma
Based on OMEC, with a focus on Fixed Wireless more than mobile.
Not fair to consider it just an EPC, Magma is highly scaleable and designed with a focus on Fixed Wireless offerings.
Supported by the Facebook Telecom Infra Project.
OMEC – Open Evolved Mobile Core
Supported by Open Networking Foundation, Sprint and several other large players.
OMEC has each Network Element in it’s own repo in GitHub and each is managed by a different team.
OpenMME – MME
In use by at least one commercial operator (in some capacity).
Next Generation Infrastructure Core (S-GW & P-GW)
Seems to only compile on 16.04 and not really
c3po – HSS / CDR / CTF
OpenCORD
srsEPC
(from the guys who produced srsLTE / srsENB / srsUE)