From Seven Seas' website, gomanga:
Since 2004, Seven Seas Entertainment has been devoted to bringing the best in Japanese manga and original English-language manga, comics and graphic novels to North American audiences. Seven Seas is also a studio capable of taking on manga and other comic-related projects. The company is based in Southern California.

Imprints:

• Ghost Ship - Mature readers
• Steamship - Mature readers
• Airship - Light novels
• Danmei - Chinese BL

Sites:
Airship
Ghost Ship
Steamship
Seven Seas Danmei

Socials:
Twitter, Facebook, Tumblr (Inactive), Comixology, Forum (Inactive)