Nothing in particular, just read up on how lighttpd and nginx differ from Apache, and why one or the other is better suited for different tasks.

For example, Apache has a lot more modules that can do obscure things that aren't mainstream for a web server. Such as LDAP, and WebDAV, these modules might make Apache better suited for an intranet setup. Even if the nginx community popped out a good WebDAV module, the Apache one would still be a better choice because of the vast documentation and larger user base and community support already available for it.