Complex sentence: While the press was originally conceived as a publisher of speculative fiction in both trade and limited editions, its focus has broadened since then, both in content and format; it now publishes mysteries and nonfiction, as well as eBooks and magazines.
Split into simpler sentences: While the press was originally conceived as a publisher of speculative fiction in both trade and limited editions, it has broadened out somewhat since then, both in content and format. It now publishes mysteries and nonfiction, as well as eBooks and magazines.