The Open Source development community has become stronger over the last several years with some successfull products being developed including Joomla, Moodle, Open Office, DotNetNuke etc. This raises the question of why develop a new software product from the group up? why not just build applications/extensions on top of existing open source frameworks? For example, Joomla has a very large developer community base, very solid arcitecture and a active support community. Developers could save time by developing extensions that uses the Joomla framework rather than building a new system from stratch. Of course, it comes down to the client’s requirements and of course a open source framework may not cater for these needs. But in general terms, if you are ever thinking about building software to do a specific “thing”, consider what open source (or even proprietary) platforms are available that you could build your application on top of.