Too many, I bet, and all of them buggy.
In recent Ubuntu alone both usplash and plymouth have come to plague users. These tools purport to make bootup "friendly", but in fact:
- Cover up important messages/warnings
- Make recovering from issues during boot well-nigh impossible
- Make boot-time fsck fragile and hard to interact with
- Interact poorly with graphics drivers (xorg or kms)
- Are much, much too hard to disable
Even better, Plymouth can't be uninstalled without ripping the guts out of an Ubuntu lucid system completely. It's wired deep into the package dependency system.
Argh. I'm coming to dread distro upgrades because I have to learn how to get rid of the blasted splash screen all over again. If only they'd stay uninstalled...