ZDoom

Since I have had the desire now to upgrade the forum software for a while now, things like this only hinder the upgrade process further.

In the event that this is added, rel="noopener" should be added to the links for improved security.

See https://mathiasbynens.github.io/rel-noopener/

Honestly, I feel like forcing something like that is forcing user choice. I really don't like it when sites do that. I have the choice to open tabs in the way that wildweasel suggests (and usually do when I'm on these forums, and many other sites) but I don't want the forum deciding to do that for me; sometimes I don't want to do it.

Is it possible to make all non-forum.zdoom.org links open in new tabs?

I'm not sure the forum software offers that kind of flexibility - what I'd advise instead is to get in the habit of middle-clicking (or ctrl+clicking) links to make them open in new tabs. Depending on your browser, there may also be a setting to always open links to external sites in a new tab.

Since Mediafire likes to hijack the current browser tab with ads, would it be possible to automatically make every download link to Mediafire open in a new window or tab?