Need for servlet-api 2.4 and jsp 2.0

[Jukka Zitting]

Hi,

What parts of Sling require servlet-api 2.4 and jsp 2.0 over
servlet-api 2.3 and jsp 1.2? How strict are these requirements?
Basically, how hard it would be to make run Sling on a 2.3 servlet
container?

BR,

Jukka Zitting