extension

Mozilla Archive Format, with MHT and Faithful Save :: Add-ons für Firefox. Asked about something like this today, my knowledge was a bit outdated, so I googled again and this seems to be the most interesting extension to save complete pages (including images, styles, and JS). Practical, for example, if you want to put together a dummy for presentations.

philikon / weaveclient-chromium. Not yet tried, it is a Chrome extension that integrates Mozilla Sync into Chrome and Chromium. With this, you could finally exchange bookmarks between Chrome and Firefox without having to go through XMarks. If someone now also builds this extension for Safari, I would be happy - the fact that I cannot properly sync between browsers, but each one cooks its own soup, is highly annoying. Mozilla Sync is free to use and behind it is a company that I trust much more in this area than all the others.