Building software from source

[Matthias Bauw]

Hi there,

I have been using Linux for quite some time now and I have installed my own 
webserver for testing purposes.

I have some question about building software though? How can I update 
software that I have built from source? 
Do I just download new source and build the new version? Will the old one 
disappear then?

And what if you want to add configuration options afterwards? For example, 
have have built PHP from source without
GD, and now I would like to use it. What do I do?

Matt.