I admit that already have some years and there is no indication that will have an update soon, but it’s a very stable software, which gets along very well with old hardware. Another viable option would be Endian Firewall, much more current than IPCop, but their requirements they may be higher. (2) Audio system going, perhaps do you need a Pentium 4 to listen to a couple of mp3? While the audio player is compatible with the operating system that you use and the sound hardware has the minimum specifications to deliver an experience stereo at 44.1 Khz, then listen to mp3s on a Pentium 133. Of course, you will have to forget about any multi-tasking operation. Mp3 decompression will claim mind and soul of the processor, not to mention an extensive process of tweaking on your part. If for some reason you have breaks in the player, you should maybe play a little with its internal buffer. Despite the current requirements of the Winamp versions 2.x are still available through the Web, and should work perfectly with your Pentium.
(3) Display images you seen the cost of a software application for viewing and editing images? Some may be as expensive as a LCD monitor. I understand that perhaps an old CRT monitor connected to a Pentium 133 is not the porta-retrato ideal, but don’t need more than a screen saver capable of displaying images in slideshow mode to achieve the same effect. At the same time, a Pentium 133 is enough to see images in JPG format. The extraordinary free version 2.43 of the ACDSee is still available on the Web, for what you have secured access to one of the best displays of yore, which I admit to having used during whole years. (4) Word processor / spreadsheet I remember a movie where someone publishes to sell online to a typewriter with the phrase text fail-safe processor.