remux

First off, this software is still maintained.
There’s a recent release on Mac update. Like other entry point video software; there’s not much to update. It just works.

Which leads me to 2.
Generally, it just works. There’s some minor issues in using this to mux early MPEG containers such as VOB, mpg, mpeg, mp1 etc. And occasional glitches with large files over 4 gb in size.
But it works just fine for modifying large files in other containers such as AVI, qt, xvd, and mkv.
So there’s a broken module.

That said 99% of what I throw at it comes out flawless. It even fixes mal-formed headers and footers. So far, excluding the far less intuitive MKTools this is the best free (as in cost) mkv muxer.
Coming from a long time using mkvmerge I was so disappointed with the eye candy interface unit I spent over a year looking for a replacement.

The interface is classical. Drag, drop, click, done.
The program is fast: very fast.
The software is stable (excluding mentioned mpeg issues)
Repairs damages to non-AV data
Add, remove tracks
Some ability to fix minimally damaged files (near-completed breaks).
Built in batching
Easy to see warnings about file overwrites.
Scriptable to a minimal degree. (Depends in system access).

This is a simple, reliable and fast way to remix things, but it has some limitations. I still use it almost everyday, and I'll explain why.

The advantage that this has over Subler is that it can convert audio from just about anything into AAC. Subler seems to crash when converting audio (I don't even know why the option is there because it crashes every single time). So unless something has AAC audio, I run it through remix first, and then through Subler to add subs, convert to Main @ 3.1, and add metadata and cover art.