altaic asks: "Today I was looking for a container format to store my anime collection (multi-language audio and subs), and I discovered popular media containers actually suck. AVIs are a hacked mess and don't even support multiple audio tracks. OGMs are catching on, but they don't have an index, nor do they support variable framerates (the fps value is stored in the header). I found some info on the Matroska container, which looks really cool (it supports multiple subtitle streams, multiple audio streams, a slew of other nice features), as well as the very young MPCF (mplayer container format). I'd really like to hear about other people's experiences with newer, more useful media containers."