Attached in a ZIP file you may find 3 search plugins respectively for All OFBiz ML List (User+Dev+Annonce), User ML and Dev ML.
I used Nabble for that. I don't know how far is the history but it works anyway.
To use it unzip files and put them in your Firefox's searchplugins dir.
For me on Windows it was : C:\Program Files\Mozilla Firefox\searchplugins, on Linux (Ubuntu 5.1) /usr/lib/mozilla-firefox/searchplugins
BTW when whe turned to new Apache ML I asked Nabble to keep the archives they have added before but they seem not to be very old...
For history you may look at
http://lists.ofbiz.org/mailman/listinfo
history of users is here for example http://lists.ofbiz.org/pipermail/users/
There is no embedded search tool but you may use google site search option
The commits ML is not already active, I will create soon a search plugins also
for it (if anyone want to do it before me I'll not be offended ;o)
Thanks to Firas A. who was the creator of the original search plugin (initially on own OFBiz ML)