The end of life problem can be solved by source code escrow, with a clause putting the code under an open source license and published in case of the demise of the owning cpmpany.
With O'Sassy specifically, the end of life problem solves itself. If the original vendor stops offering the software, a third party offering the software is not competing with the original vendor. Thus, the third party can offer paid hosting for the software if the original vendor does not.
This is the entire point of Fair Source undergoing delayed Open Source publication -- to codify the forward-path into the license itself, without the need for external source code escrow services.
