Hello, from a previous RLlib version I know that QMIX and VDN were included, but now they are not available as training algorithms. Do you plan to include them back in the future?
Hi @ardian-selmonaj,
the QMIX algorithm is still available in our old stack in rllib-contrib (see here).
If we include QMIX again in the new stack is unclear, yet, and if so will only come after the Summit. VDN is not in discussion.
It seems that rllib-contrib is gone. 
Is there any plan to add it back?
@jiangpeng_li That is true, we deprecated these algorithms for goopd because they are all written in our old stack and new stack is now the only supported one.
You can always roll back to an older RLlib version (because these algorithms are not changed anyways by us) and use this version to run them.
Every version below ray==2.37.0 should make it.