The aging Netscape Communicator 4.x was slower than Internet Explorer 5.0. Typical web pages had become heavily illustrated, often JavaScript-intensive, and encoded with HTML features designed for specific purposes but now employed as global layout tools (HTML tables, the most obvious example of this, were especially difficult for Communicator to render). The Netscape browser, once a solid product, became crash-prone and buggy; for example, some versions re-downloaded an entire web page to re-render it when the browser window was re-sized (a nuisance to dial-up users), and the browser would usually crash when the page contained simple Cascading Style Sheets, as proper support for CSS never made it into Communicator 4.x. At the time that Communicator 4.0 was being developed, Netscape had a competing technology called JavaScript Style Sheets. Near the end of the development cycle, it became obvious that CSS would prevail, so Netscape quickly implemented a CSS to JSSS converter, which then processed CSS as JSSS (this is why turning JavaScript off also disabled CSS). Moreover, Netscape Communicator's browser interface design appeared dated in comparison to Internet Explorer and interface changes in Microsoft and Apple's operating systems.