Before doing the compare, I'll digress a bit with the background story.
Recently, my old Mum of 93 years could not get her Gmail. I checked her old Toshiba Satellite Pro L20 with 256Mb RAM and slow processor was so out of date with WinXP and Thunderbird and Firefox. Gmail refused access as their policy precludes out of date software loaded PC.
Mum only totals about 10 emails a month, so shes relatively happy with dial-up (do you remember that old internet method ;-)
My first thought was to dump XP and replace with a lightweight Linux distro eg Macpup or Lubuntu. Unfortunately, they dont easily talk with windows modem cards so that option was out.
Initially I needed to upgrade to WinXP SP 3, replace Thunderbird with a later version and finally replace the Browser, which resulted in a much faster PC but still no Gmail :-(
The real cause of problem was mail.google had decided to disallow her computer after many years of Gmail. To reinstate access even after upgrading her machine, I had to go to Gmail login via web browser and Allowing less secure apps to access your account.
My opinions are based on how fast the browser loads, its features and user interface vaguely compared to my Firefox which is a pretty good browser.
MIDORI Ive used in the past, and its a great browser, but with Mums old computer it would partially load, then lock up. Others report this issue as well. Thats why its not included here. Incidentally, Midori shows over 200Mb memory use much more so than Firefox. This is possibly part of why it failed.
DILLO potentially had the goods, but after installing it and running it, found it has such a bare-bones approach as to be unsuitable.
It will not load some server contents, single panel, no frills. Its achieves its purpose of being a minimalistic very lightweight browser, but I found it too minimal.
LYNX BROWSER is minimal command-line browser so it was excluded as were several browsers which only work in Linux Platform.
SLIMBROWSER I couldnt get my head around this one. Its only about 3Mb download and certainly lightweight and seems to have most features I wanted but advertising abounds and it reeked of insecurity eg spyware. These concerns could be wrong, but I guess give this one a try and see for yourself.
SLIMJET is a stripped down version of Chrome. Had potential, but would not load up on Mums computer so no comments.
K-MELEON What they say: it's an extremely fast, customizable, lightweight web browser based on the Gecko layout engine developed by Mozilla which is also used by Firefox. K-Meleon is Free, Open Source software released under the GNU General Public License, DNS and is designed specifically for Microsoft Windows (Win32) operating systems.
Its been around for some years and is the best option for low-resource WinXP PC that Ive found. It loads in 30 seconds even on Mum's PC which takes 5 minutes to load windows and default Thunderbird!! It used to take about 5 minutes to bring up Firefox. K-MELEON functionality is great and seems to be a very compatible browser with Java pages and so on loading up nicely. As far as the GUI they have kept it simple and some things dont seem intuitive, but that could be my personal opinion. Nothing is a big deal though and I highly recommend this as a replacement on your aged PC. If only they would give it a better name!