Both Cuis and Squeak (from which both Pharo and Cuis were forked) are still actively developed. Pharo does have the largest presence in the two major Smalltalk

Both Cuis and Squeak (from which both Pharo and Cuis were forked) are still actively developed. Pharo does have the largest presence in the two major Smalltalk conferences (FAST in Argentina and ESUG in Europe) but there is no need to worry if one of the other options is more aligned with your needs.