5.6 is a bugfix release.
vimdiff http://download.webconverger.org/webc-5.5.txt
http://download.webconverger.org/webc-5.6.txt
reveals the usual browser
updates.
The change to webconverger-base fixes the home button when more than one URL is specified on the boot command line.
Lately I have been exploring static Firefox builds, as I hope they may help make upgrading manageable. Also if you are a bit of a browser geek, checkout the Webkit-based surf browser.