The odd thing is, there are a few ACM implementations of the excellent Open Source "lame" MP3 encoder out there, but so far I have been unable to find one that RMM will work with.
I'd better check whether we even claim to support that in current RMM. At one stage at least we were considering skipping that for first release, as all the ACM Lame encoders we found were so utterly nonstandard ACM that we couldn't come up with a common subset of features that actually worked. Either way, we hope to improve support for third-party encoders in future (free, Web-upgradable) releases of RMM. We can't install any of them with RMM for patent reasons, but I reckon that if users have previously installed one themselves then we can assume that they've taken care of the patent thing, or perhaps are in a no-software-patents country.

Peter