[horde] dom-xml php requirement for horde3

[Alejandro Lengua - Virtual Orbis]

This is not exactly a Horde3 question, but is about and Horde3 
pre-requisite.

Could anybody point to a document where I could see how to install the 
dom-xml, please?
I have trying adding the --with-dom command, but it seems that I need to 
install a PECL
lib. However I can´t find info on how to install it either from Pear or 
compiling it directly.

Thanks in advance
Alejandro Lengua