Preparation

To download the source you will need a subversion client. Linux distributions typically come with a command line svn tool. Tortoise SVN seems popular on windows.
You will also need maven and a 1.5 JDK. Maven can be downloaded from Apache Maven Site

Choose and download a source level

Tuscany's Java source can be found in subversion at https://svn.apache.org/repos/asf/incubator/tuscany/. You can either build directly from HEAD, or use one of the tags. Building from head means you'll always be building the latest stuff... however, the down side of this is that it's unstable and may sometimes fail to build. The following table should help you choose what to check out. You'll need a subversion client to

Branch	Comment	Subversion checkout
HEAD	The very latest, includes changes for the 1.0 SCA specifications. Not really a branch, but you know that . This is actually SCA, SDO and DAS, but there isn't a neat "download just thew SCA part of Tuscany URL that I'm aware of...	svn co https://svn.apache.org/repos/asf/incubator/tuscany/java/
pre-spec-changes	SCA for Java as per the 0.95 version of the specification, should be more stable than head	svn co https://svn.apache.org/repos/asf/incubator/tuscany/branches/pre-spec-changes/
sca-java-M2	This was/is the milestone 2 release, you probably don't want this	svn co https://svn.apache.org/repos/asf/incubator/tuscany/branches/sca-java-M2/

Why https ? If you prefer you can use http instead of https. Personally I've found that https is more reliable than http, however I think this may be down to my local network and invisible proxies.

Do you need to overlay, or can you just download the tag and mvn from there ?

Build it

Building "HEAD"

Building "pre-spec-changes"