McIlroy--Winning Battles, Losing Wars

Quark championed the concept of allowing third-party software developers to plug their wares into a major application, effectively recreating the core program. Using what Quark called "XTensions," hundreds of smaller companies helped make QuarkXPress extra-well-suited to a series of different types of publishing functions and operations, from newspaper publishing to Web design. The core page layout functionality of QuarkXPress remained unchanged in each variant, but custom features added support for operations such as version control or precision kerning. As a result, QuarkXPress could move from being merely a very good application for designers and publishers—to being a great one.