Beta versions of Limewire use now an odd number in the second digit, and an even number for releases.
The third number indicates small patches or corrections to a beta or release.
So version 4.3.x is a beta.
Now that 4.4 has been released, you'll may see new 4.4.x versions for releases that include minor corrections (but no addition of functionality), and 4.5.x versions for betas (that include new features not added in the 4.4.x branch).
Limewire is then developped on an odd branch, while the latest release may include patches retrofitted from the beta to the last release version).
For now, there's no 4.5.x beta, but it may come soon, to test new features. The current release is 4.4.4 (4.4.5 *may* be released soon with an updated Dutch translation, or few minor bugs corrected, but no additional feature).

So when you try a beta, get sure to use the latest odd sub-version number. Betas (odd) versions x.y.z are no longer supported or discussed here for changes once there's a release x.(y+1).* version on the main download site...

Sometimes, a new release "x.(y+1).*" will be made without some features which were tested in beta "x.y.*", but in that case, these features are delayed and will possibly be present again in the next beta "x.(y+2).*".

When a beta has integrated major changes or additions (such as supporting a new protocol, or an improved GUI interface), the second digit will be 9 (for example the betas to test the next major release 4.0 were "3.9.*"). Beta sub-versions 9 will come just before Limewire thinks that a major update will be beneficial to the Gnutella community, due to important protocol additions or changes (for example the major version 4.* integrates now new protocol features to work through UPnP-enabled routers and firewalls, and is an adequate response to the new Windows XP SP2 builtin firewall; it also includes a new Firewall-to-firewall transfer protocol, based on UDP, which allows emulating a TCP session through a couple of firewalls on both ends).

Here, we should discuss either about the odd beta versions available via the "Beta" button on the Limewire download page, or about alpha versions manually compiled from the instable CVS sources in the Limewire repository (these compiled versions from the CVS sources do not show their version number but just display "@version@", and should not be used for long as they may contain many instable and uncorrected bugs, or premature new code which is not fully tested.)

Those that compile Limewire themselves (using the JDK tools and the various libraries documented in the limewire.org website) must then be prepared to update their sources quite often, or should get a stable version using a branch marked by the Limewire team for each official beta or release: this is normally not needed, for someone else than true developers, because you'll get the same things simply by downloading them from the Limewire website where the application is already compiled).

If your CVS sources is older than 1 month, please stop using it, and download an official precompiled installer or update your sources and recompile)!