I have an old - and I mean old - laptop sit in my bathroom I use for reading random-ish Wikipedia articles, and it's too puny to run any mainstream browser. I used to use Dillo, which is fine resource-wise, but I grew annoyed over time that it does not have session management.

Then, recently, it hit me - w3m-mode has both tabs and session management. It somehow even displays images more reliably than Dillo. I wouldn't use it as my main browser on the desktop, but for my specific use case, it's perfect.