Beginning with version 3.1.0 Breadcrumb NavXT will probably retain a WordPress 2.7 and newer compatibility mode (rather than the current WordPress 2.5+ compatibility mode that is in place right now). This is due to some API changes that are being phased in with 2.7. 3.0.x will work perfectly fine with WordPress 2.7, but with WordPress 2.8 the administration interface may break (option saving/setting wise).
For my other plugins, both Mtekk’s Testimonials and Iframe-b-Gone are not fully compatible with WordPress 2.7. Mtekk’s Testimonials does work, but needs some tweaks. Iframe-b-Gone is more or less obsolete, and I really do not plan on continued maintenance of it. Comment Code Filter is 100% WordPress 2.7 compatible. Moo.wp and RPC Utilities are both very old and I doubt either still work. Moo.wp is no longer needed thanks to the script enquery tools in the WordPress API. RPC Utilities stopped working at around WordPress 2.3 or 2.5. I plan on eventually revisiting it, though that will be after Mtekk’s Testimonials gets updated.
-John Havlik
[end of transmission, stay tuned]