Are you planning anything special for the big version 100?
Nothing huge, no. It will feature some new application icons (that look mostly like the old ones, but a kind user made scalable variants for them), and I’ll try to tackle the issues that were reported around the “run programs after job finishes” feature over the last couple of days. Apart from that… nothing in the pipeline.
I will definitely look at support for AV2 when that’s finished/finalized which is right around the corner (I think), but even if that was finalized right now I would probably not have it done for v100.
Round numbers aren’t such a big thing for me in general. Personally the release of v77 was more more important to me, even emotional, as that marked 20 years of developing & releasing MKVToolNix (first release was on 2003-05-03).
It’s honestly remarkable that you’ve stuck with it so long since life can change so much in 20 years.