Before torrents and yet similar to them there was Kazaa. Kazaa Lite is a slightly more modern (but still fairly aged) piece of software that provides the Kazaa network with none of the infamous malware or software restrictions. Though few people still use Kazaa today K-Lite as it was known runs and still does see some use.
No restrictions for good or ill
Kazaa Lite has the distinction of being an unsupported application from the early 2000s. This means that there really aren't many people who will tell you how to use it and you can pick and choose which modern updates you use without worrying about incompatibility. But it also means you have to do some of your own work to use it. Kazaa Lite by itself won't run on modern operating systems for example.
Niche but good
Overall that makes Kazaa Lite worth using for users who want a more out-of-the-way file-sharing experience who are looking for specific things and will try everywhere to find them and who have the patience to deal with its small number of users and the blemishes that it's shown over time. In other words if you're a power user looking to get access to everything that's out there on the web the Kazaa network is still running and in use.