The archive contains a port of SeaMonkey as well as the therefore needed, but deprecated port of lang/python27; Note that lang/python27 is just a build dependency, and can be removed afterwards.

Updating from version 2.49.5 or earlier means "no way back" (or: "use your backup") as the user directory isn't backward compatible.

For a faster build process you may want to check if the following packages are installed on your machine: cmake gmake gtk2 gtk3 llvm13 rust-cbindgen; But consider that pre-installing those dependencies will set them to a "non-automatic" state, while the build process would leave them with the "automatic" flag; So you've got to take care of getting rid of them again by your own – a simple pkg autoremove won't do that for you…

If you don't want the english user interface take a look at the available language packs. To get the spellchecker up & running you have to install a dictionary addon (don't forget to select that dictionary also in the preferences). And if you're looking for a working version of "uBlock Origin" – here it is.

This port needs ImageMagicks bindings for Perl. As they aren't enabled by default you also need to compile the port graphics/ImageMagick7; Just having the package installed won't work.

Backed port: At time of building this "ports extensions" this was the actual and official state of that port; It's just included because it will be removed from the ports tree soon. But as it's needed to build SeaMonkey: With this you're able to pull it temporarily in even if it's officially gone.