Earlier this year I wrote about a little-known protocol called ICA which made it possible to deliver complete Windows desktop environments across networks and phone lines to client PCs and X-terminals. Developed by Citrix Software, ICA is a key component of the company's WinFrame product - an extended version of Windows NT which supports multiple users using the system at the same time from remote locations. The great promise of ICA was that even over 14.4k modem lines it was possible to open and work in a complete Windows environment running on a WinFrame server. Even someone with a DOS PC could hook up to a LAN and run a full graphical Windows desktop off the server. But with the explosion of the Internet, Citrix can use ICA for a whole new purpose: application delivery to the Web browser. Using an ActiveX control developed for Internet Explorer, it is possible to launch an application from a WinFrame server embedded in the middle of a Web page. The promise of this is that the Web browser can become the default client work environment: it becomes the mail and news client, the front end to the Web and ftp and now the application deployment engine of the future. Because applications run on central servers, they are easier to administer and maintain and the client-end is no longer platform dependent. Groups expected to benefit from the technology include large PC-based corporations, who can decrease their client-end maintenance costs by deploying server based solutions, and ISPs who have already started exploring the possibility of selling access to Windows applications to their users. But, the most intriguing potential beneficiaries are software developers. Many shareware and commercial software vendors offer free copies of their products on the Internet. These applications have to be downloaded and installed by users and the licence terms under which they are distributed are often breached by consumers. Software vendors rarely collect for each copy of their package in use and registered software is often copied and disseminated by people who either do not realise they are violating licences or do not care. With the ICA control for Internet Explorer, it is now theoretically possible for software vendors to offer their wares without the user ever installing the application on their local system or being able to distribute it to other users, thereby violating the licences. It is possible to legally use a product such as Microsoft Word or CorelDraw off a public server.