I am new with Lift and want to know if it is developed to just run with Jetty but no other web server. Any idea?
Lift works great with Jetty when you are developing, but you can certainly run it on other servlet containers. Tomcat seems to be a popular choice.
From wikipedia: Lift applications are packaged as WAR files and deployed on any Servlet 2.4 engine (e.g., Tomcat 5.5.xx, Jetty 6.0, etc.)
Here is a tutorial explaining how to run Lift on Glassfish v3
Lift is primarily deployed under Jetty because Jetty is the only container (that I know of) which is supported by Lift 1.0's continuations integration mechanism. Without a container which supports continuations, Lift's Comet support is unoptimized and every single client (literally!) will hold at least one thread. Obviously this doesn't scale.
AFAIK, Lift 2.0 has gone to the standard Servlet continuations API, so it supports more containers, but I believe that Lift 1.0 is generally coupled to Jetty for high-performance Comet.