I’ve been using Firefox for web browsing for the last year or so, but it has become a bit of a memory and resource hog for my slightly underpowered laptop (a Dell X1/Samsung Q30 ultraportable), which has only 512 MB of RAM – it doesn’t take that much to ratchet up its memory usage to 100 MB and beyond. Googling “lightweight browser”, two which came highly recommended were Opera and Kmeleon. Opera has a lot of the functionality of Firefox without having the need to download a bunch of plugins at the start, but I found it only slightly less memory-intensive than Firefox. Kmeleon on the other hand is small, and very, very fast (it’s built on the native Windows API) – it shares the same rendering engine (and same standards compliance) as Firefox, has fewer frills and conveniences, but just about everything I need when I’m surfing at home. For my laptop, it’s perfect – it’s free, offers incredibly speedy browsing, and gives me enough space to run other apps such as Word or iTunes.
In a similar vein, I looked for an Adobe Reader replacement, and found the free and open source Sumatra PDF – it runs as a standalone EXE without the need for installation, and is tiny – 800K is all the disk space it takes. Again, blazingly fast relative to its predecessor, simple and minimalist, while still meeting my rather modest needs.