Just because it hasn't seen activity in awhile doesn't mean it can't be used at all.

Sure, you're not going to want to start up a major project with a long-abandoned language experiment, but frankly it's not much of a step down from even an active language experiment.

I suppose it's got a greater chance of being harder to get going, but so much of that depends on how it was built in the first place that simply being older isn't enough information make much of a guess on that either.