In Audacity (open-source audio editing program)
I was trying to get a gradual speed change effect. Along the way, I learned
that Audacity can use various plugins
and you can make your own
VST plusings with Synthedit. But
anyway, like Dorothy, what I wanted was there all along in Audacity. It’s
called Time Track. Project->New Time Track menu. Alas, there is a bug that crashes it if
you try the Set Range option. bleh.