Don't know if anyone at Sentry will read this, but I think the idea of the Functional Source License is pretty interesting.

But is it customizable? e.g. does the source has to be made available 1 year? How about 2? How about 1.5?

How about something like FSL-Y2-MIT for a 2-year limitation? You could still use FSL-MIT for the standard 1 year term.

Then you could maybe allow quarter- or half-integer values, e.g. FSL-Y1.5-MIT or FSL-Y0.25-MIT.

All of this easily represented in the name or with minimal digging.

Just wanted to throw in my share of the bike-shedding.