I debated whether to respond to /u/shanoxilt's thread asking if anyone was interested in collaboration with this, but since it was a ways down I figured this might warrant a new thread.
I have an idea for a collaborative project that would take multiple stages:
Stage 1: Participants separately construct alien cultures and languages for them
Stage 2: Participants show each other their cultures and languages and try to arrive at a consensus for a plan and outline of an auxiliary language between the different alien cultures. The nature of this auxiliary language can be decided in this stage as well; it may be a pidgin, a form of one of the specific languages, an in-universe constructed language, etc.
Stage 3: Participants collaboratively flesh out the details of the auxiliary language.
Possible Stage 4: Participants evolve the auxiliary language.
Possible Stage 5: Participants split the auxiliary language into dialects, with a possible premise being the loss of contact between the civilizations.
Is this too big? What would be some ways to handle inevitable issues like people dropping out, etc.? Has something like this been done before?