Apache XML project (Popularity: )
http://xml.apache.org/ Different open source tools, most of which use the Xerces implementation (DOM Level 1 & 2) as a base. Xerces ...
xmlBlaster (Popularity: )
http://www.xmlBlaster.org/ XML and CORBA/RMI/XML-RPC based MOM (message oriented middleware) for Java/C/C++/Perl/Tcl/Python. Free for commercial and non commercial use (LGPL).