Fusebox 5 introduced the idea of custom attributes for the <fusebox>, <circuit>, <class> and <fuseaction> XML tags, using XML namespaces. Fusebox 5.1 extends this to <plugin> declaration tags as well. If you think other tags should also have custom attributes, let me know.

The <relocate> tag gets a couple of new types: moved and javascript. Previously you could specify client (the default, equivalent to ColdFusion's <cflocation> tag) or server (which uses server-side forwarding to a new Servlet request). client generates a 302 Moved Temporarily response but sometimes it is useful to return 301 Moved Permanently instead - moved lets you do that. The javascript option generates JavaScript code to change the location - which is useful if you've already sent HTTP headers, for example.