It's mostly a standard Xubuntu with full disk encryption (just in case the machine gets stolen while travelling) i3 might be even better. I use that at work, but was too lazy to configure it on this machine.

I have desnapped it though and download Firefox directly from Mozilla. There is no Chromium on it.

Edit: I know that it would choke on opening an ever growing number of Firefox tabs. I just close them. And I don't run the machine for more than a couple of hours before shutting it down. Don't use suspend at all.

Edit2: It uses swap. Don't remember whether that was the standard setup or whether I added it myself. Of course you cannot rely on swap for responsive operation, but it helps parking some unused data because the desktop/distro is not optimized at all. And it helps you to get over a tight situation when you forget to close something. When it slows down it's a nice reminder to do so.