By Prince McLean

Published: 08:00 PM EST (05:00 PM PST)

Former chief executive of Sun Jonathan Schwartz has accused Steve Jobs of threatening patent action against his company in 2003, related to desktop OS technologies, in a long blog post that highlights a series of tech patent squabbles.

Schwartz introduced his blog posting commiserating for Google, although Apple's current patent lawsuit is actually being taken against HTC, the hardware partner behind the Google-branded Nexus One, and does not directly involve Google at all.

HTC also makes most of the other significant Android phones on the market as well as a number of high profile Windows Mobile phones, both under its own brand and cobranded with other companies.

Schwartz said that Jobs called him personally in 2003 "to let me know the graphical effects [in Sun's Project Looking Glass project] were “stepping all over Apple’s [Intellectual Property]." If Sun decided to release the product commercially, Jobs reportedly threatened to sue for infringement.

Schwartz said that Sun chose not to launch the product in question, but that the decision was not affected by Jobs' threat. Instead, he said Sun abandoned the Linux desktop user interface shell because it thought there would be no market for a Windows desktop competitor among businesses.

The point of the blog posting was further muddled by Schwartz's comments that Apple's Keynote app was likely infringing on intellectual property in Sun's Concurrence. It is an open secret that Apple based elements of its suite of iWork apps on a series of productivity apps created by Lighthouse Design for Jobs' original NeXT Computer.

Schwartz was a cofounder of Lighthouse, and therefore an associate of Jobs during his stint at NeXT. The Lighthouse apps were "the Offices suite" for NeXT, and were a personal favorite of Jobs. NeXT needed Lighthouse because Microsoft had refused to port its Office apps to the platform, with Bill Gates famously saying he'd rather "piss on it" than develop apps for the advanced operating system Jobs created after leaving Apple.

However, when Sun bought Lighthouse in the mid 1990s, it locked up the company's suite of apps and threw away the key, abandoning all new development. Apple was then forced to create a Cocoa-based productivity suite on its own over the last decade, as Sun had no interest in developing for Cocoa because it was then focused on pushing Java.

Microsoft only begrudgingly did the least amount of work necessary to get its existing Mac Office running on the new Mac OS X, using Apple's legacy Carbon environment rather than porting Office to use the advanced new Cocoa frameworks.

Apple is now touting iWork as a suitable replacement for Office on the Mac desktop, and debuting it as the first multitouch productivity suite, developed for the upcoming iPad.