What is difference between Extended support and Source code escrow?
If you purchase Extended support, you will also get source code if CoqSoft will be bankrupt. The difference is in warranties. Source code escrow is guaranteed by U.S. company Lincoln-parry SoftEscrow (called escrow agent). In this case, you will get TreeGrid sources in case of described event from the escrow agent independently on CoqSoft. On other hand, Source code escrow is just escrow, but Extended support also contains free upgrades and priority in requests. Therefore the two options cannot be substituted and you can purchase even both, if you need warranties and free upgrades.