What should I use under *nix instead of freeze?

[Mike Kent]

In a comment Guido made on a recent bug report for the 'freeze'
utility, he stated:

"I think nobody really cares about freeze any more -- it isn't
maintained."

That being the case, what is the preferred/best replacement for freeze
on a *nix platform?  I'm looking for something that, like freeze,
turns my application into a single-file executable, of the smallest
size possible, that can be executed on a machine with no Python
installation or development system.