feel of widgets by deriving from the default, another existing one, creating one from scratch, or, beginning with J2SE 5.0, in an XML property file called synth (skinnable look and feel). Lawsuits Some companies try to assert copyright of trade dress over their look and feel. The Broderbund v. Unison (1986) case was an early software copyright case that attempted to apply U.S. copyright law to the look and feel presented by a software product. In 1987 Lotus sued Paperback Software and Mosaic for copyright infringement, false and misleading advertising, and unfair competition over their low-cost clones of 1-2-3, VP Planner and Twin, and sued Borland over its Quattro spreadsheet. In December 1989, Xerox sued Apple over the Macintosh copyright. Apple Computer was notable for its use of the term look and feel in reference to their Mac OS operating system. The firm tried, with some success, to block other software developers from creating software that had a similar look and feel. Apple argued that they had a copyright claim on the look and feel of their software, and even went so far as to sue Microsoft, alleging that the Windows operating system was illegally copying their look and feel. Although provoking a vehement reaction from some in the software community, and causing Richard Stallman to form the League for Programming Freedom, the expected landmark ruling never happened, as most of the issues were resolved based on a license that Apple had granted Microsoft for Windows 1.0. See: Apple v. Microsoft. The First Circuit Court of Appeals rejected a copyright claim on the feel of a user interface in Lotus v. Borland. More recent reactions In 2012 and 2014, Apple Inc. has filed lawsuits against competing manufacturers of smartphones and tablet computers, claiming that those manufacturers copied the look and feel of Apple's popular iPhone and iPad products. In APIs An API, which is an interface to software which provides some sort of functionality, can also have a certain look and feel. Different parts of an API (e.g. different classes or packages) are often linked by common syntactic and semantic conventions (e.g. by the same asynchronous execution model, or by the same way object attributes are accessed). These elements are rendered either explicitly (i.e. are part of the syntax of the API), or implicitly (i.e. are part of the semantics of the API). See also Design language Lotus "look and