I usually provide support by email. However, often enough the issues brought up by users are generally interesting for a wider audience. And, just as often, I have to answer the same question over and over again.
Therefore I decided to open a forum for MKVToolNix in particular and Matroska in general. Everything about my programs and Matroska is ontopic there. It’s a StackExchange like forum that uses the excellent Questions2Answer software.
Feel free to come around. I’ve added all of my earlier FAQ entries as posts, and a couple of other questions have been asked by new members as well.