Open Access Publications (OAP) is a new OA journal publisher.  (Thanks to Jim Till.) 

OAP will allow authors to retain copyright.  Though it doesn’t indicate what license it will use, it will offer libre OA, allowing "any third party the right to download, print out, extract, archive, and distribute the article as long as its integrity is maintained and its original authors, citation details and publisher are identified."  It will charge a publication fee of £499.

OAP’s first journal is Single Cell Analysis, whose inaugural issue is still forthcoming.