The latest nightly builds of Mozilla Firefox include a new feature that significantly improves the speed of the Back and Forward buttons. When using Back and Forward in older builds, the page is retrieved from the local cache rather than the Internet but Gecko still has to reparse the HTML and use it to rerender the page, which can take a while with more complex documents. With this new feature, the rendered page is kept in memory, which makes Back and Forward performance much faster (almost instantaneous). In addition, going back or forward to a page cached in this way shows the page exactly how it was when you left it, in compliance with section 13.13 of RFC 2616.
The blazingly fast Back and Forward feature is currently disabled by default. See Chase Phillips’ weblog post for instructions on turning it on. It is hoped it will be enabled by default in time for the release of Firefox 1.1. More technical details can be found in bug 274784 (no unnecessary comments please). Experience from other browsers (Opera, Internet Explorer and Safari have similar features) has shown that this is a tricky thing to get right without breaking a lot of pages.
[ Read ]
It is a neat feautre, try Opera and you know it is fast to navigate back and forward.
But, I do not recommend you install the nightly build. I installed it yesterday night, at first it did not load all my firefox extensions. After restart Firefox, it lost my bookmarks and the back and forward buttons did not work!
I had uninstalled the nightly build and install back current stable release Firefox 1.0.3, everything back to normal again. I think, we should patiently wait until Firefox 1.1 released.