I'm assuming that since you wish to release it as an applet, you want it to be able to run without the user having to install an extra package?
If that is the case, then you would have to write a pure software renderer and get it to decent speeds. It's possible (ala. Runescape) but not easy.
And there is a limit to how fast such an engine can be.
My personal opinion,
is that I would be more interested in writing the actual game then have my time taken up with writing software hacks for something which really should be done in hardware.
So I would use an openGL binding, and finish the game first.
Then after that, if I wanted to broaden my audience, I can a write a software renderer so that users can play without installing anything.