@timofonic I have been looking in that direction, too. However, gdcl is just a wrapper and it's written in Ruby. Both would introduce serious performance penalties. Still, it's a hopeful development.
For now Chrox seems to have a good grasp of sdcv and has introduced a few meaningful enhancements into koreader's dictionary use. Especially, the option to look up a word in the dictionary itself is nice, since it will allow for the use of synonyms.
That part of the development will be strengthened when I finally get around to sort the 8GB tarball of the Stardict dictionaries into those unburdened by copyright and those not, make them available in a repo and write an dictionary download plugin together with chrox.
This would also alleviate the problem mentioned: "
For users of GoldenDict who have large collections of dictionaries in other formats (e.g. DSL or BGL), converting and maintaining two parallel sets of dictionaries is not a practical solution." A separately maintained repo for uncopyrighted automatically downloadable Stardict libraries seems a rather practical solutions if it becomes a community effort. All we seem to need is a good start with the sorting of the 8GB tarball.
What would be nice is a separate dictionary plugin, that would allow for less sparse dictionary entries: with images and preformatted text. The performance penalties due to ruby-to-lua-wrapper, command-line-to-goldendict-wrapper and the goldendict dictionary itself would than be something the user can choose to use or not.