I have a number of files in this format that I'd like to burn to DVD. TmpgEnc won't even look at it. What free software will do this?

Go over to VideoHelp.com's guides and filter on "XviD to DVD" and "DivX to DVD" and also "AVI to DVD".

I've had decent luck with a tool called "DIKO". (You'll have to search for it.) It's slower than some processes that take three different tools, but it's all in one, so you can pretty much set it to go and come back later with a DVD image ready to go.

I use TMPGEnc XPress. It's not free, but it works great.

Thanks for that guys. On that site Bitt provided I found a nice wee application that does what I need - gui4ffmpeg.

I'll check out TmpgEnc Express (never knew it existed!). Thanks!

I tried the trial of Tmpgenc Express but it won't open xvid files

Have a look at Afterdawn, they've got excellent tutorials and provide links to the (mostly freeware) programs:

http://www.afterdawn.com/guides/