Mantel confirmed he was leaving the Waltham, Massachusetts-based Linux and identity management software vendor in a posting to a SUSE mailing list. I just decided to leave SUSE/Novell, Mantel is quoted as writing. This is no longer the company I founded 13 years ago.

Mantel founded SUSE in 1992 with Thomas Fehr, who also joined Novell when it acquired the company, as well as Roland Dryoff, and Burchard Steinbild. Mantel expressed his confidence that Novell would find a competent successor very quickly, noting there are lots of extremely skilled people over there in the Ximian division that Novell acquired along with SUSE in 2004.

Nevertheless, Mantel is the latest in a series of high-profile resignations from Novell. The company’s chairman and CEO Jack Messman denied in May that Novell was experiencing a brain-drain following the departure in quick succession of vice chairman of the office of the chief executive, Chris Stone, chief technology officer, Alan Nugent, and EMEA president and former SUSE Linux CEO, Richard Seibt.

Matt Asay, co-founder of Novell’s Linux Business Office and former director of open source strategy at the company, also left recently to take up a post at open source content management startup Alfresco Inc.

Novell has been under fire from investors in recent months and has recently taken steps to restructure its workforce to improve its performance, appointing Ron Hovsepian to the role of president and COO, and Thomas Francese as president of EMEA, as well as announcing plans to lay off just over 10% of its workforce, 600 people, by the end of the year.