There wasn't much of a B5 EU. However, Mongoose Publishing wrote a ton of splatbooks for B5RPG that filled in a lot of gaps.

The sad reality of Babylon 5 is that it is probably a complete work. It's doubtful a remake will ever be attempted, and without a remake it's doubtful any spinoff pitch would float after how badly Crusade fell flat.

There wasn't much of a B5 EU. However, Mongoose Publishing wrote a ton of splatbooks for B5RPG that filled in a lot of gaps.