Same here. I actually started from GNU's https://debbugs.gnu.org instance, wanted to make this same suggestion but didn't even know where to make it. Their footer says:
[GNU bug tracking system](https://debbugs.gnu.org) Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson. where https://debbugs.gnu.org tells me everything about how to *use* the tracker but nowhere what code powers the tracker, where to discuss issues and what's the license. Some searching lead me to the original bugs.debian.org instance, whose footer says: [Debian Bug tracking system](https://www.debian.org/Bugs/) Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson. and again the https://www.debian.org/Bugs/ link tells me how to use the software but not where it is. It took some more googling to stumble on https://wiki.debian.org/Teams/Debbugs (which is great). It shouldn't surprise people that Debian & GNU use a bug tracker that is itself free software. Still, having just a copyright line, with no mention that it's free software (and where it lives) misses an opportunity to reinforce the norm that hosted web software can and should be inspectable and modifiable by users. And of course having a link would make contributing a tiny bit easier.
