I worked a fastpitch league here that played 75 minutes, or 5 innings, whichever came first (usually the time). They had an interesting rule, that if the pitcher walked 4 straight batters, the offensive coach came in to pitch, calling only strikes. Forces them to hit the dang ball! They also had a 12/10/8 rule, but never kicked in because of time limit (and no, I'm not joking!). They also had a rule that in the last ten minutes, if a new inning started, each team was allowed a maximum of 5 batters or 3 outs, whichever came first. They paid $25 per game for this league.

Another league I worked in, had the 12/10/8 rule, 75 minutes time limit or 7 innings, which ever comes first. They also had a limit of 10 batters per inning. Once they reached the 10th batter, the first dead ball after that batter completes her turn at bat is the end of the inning. They also had a rule that stealing home was not allowed. Got paid $20 per game for this league.