Sebastopol, California-based Safari Books Online, a publisher of on-line, digital reference libraries which is backed by O'Reilly Media and Pearson Education, said today that it has added books from Manning Publications as part of its online digital library. Manning is a publisher of computer technology books, geared toward programmers, software engineers, system administrators, and designers. Safari Books already includes books from Prentice Hall, O'Reilly media, Addison-Wesley Professional, Microsoft Press, and many others. Safari sells digital subscriptions and access to reference and other technical books, which are searchable and accessible online. The firm's services are geared toward software development reference and other similar uses.