I want to install Lingerd on my VPS Servint server.
http://www.iagora.com/about/software/lingerd/
If I install lingerd, will cpanel apache update normaly?

Cure,

Judging from the installation manual - you would need to manually recompile apache each time to include lingerd.

There is actually a module that would handle the same thing - but I've forgotten the name, but it would save you the hassle of a custom compile.