Ninite.com seems to be doing it currently. I'm wondering how.
While it's possible for them to have every combination of app pre-generated, it seems unlikely/hacky.
[EDIT]
Is compiling a Windows executable using this method resource-intensive? Can it be done ~100k times a day without exorbitant cost? I'm asking because Ninite announced that they're going paid-only... can it be costing them that much?
[EDIT2]
The downloads aren't huge, it's just a small hundred KB web-based downloader+installer app that knows which apps to install.
^^ Regarding this, the EXE file served up by the webapp is named something like Ninite AIMP Audacity Chrome Digsby FastStone Installer.exe when given 20+ apps to install. It's probably likely that the server is serving up the same file under different filenames, and the app is then configuring itself based on the filename, no?