You mean "this website is optimized for Internet Explorer 6" days? Or the earlier "this website is optimized for Netscape 2.0" days?
I think the nearest the web ever came to not being any megacorp's playground was when Firefox was at around 30% market share, and IE6 which had 60%+ market share had stopped moving. IOW, when MS still had the playground mostly to themselves, but chose to ignore it. And even then, the web / Firefox couldn't really innovate without breaking IE6 compatibility, so everyone was stuck.
Sounds kinda similar to what you are looking. It does No. of sites, custom columns, custom pictures, and custom backgrounds. It really gives you a lot of control compared to all the other extensions I tried.
To get around this limitation, one could set up a personal speed-dial start page.
see: https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/Web...
they also have most requested urls as a privilege too so it could be recreated and extended with a little effort.
It has become a little more customisable now, thankfully.