Because source code takes less time to transfer than compiled code, Curl applications are delivered to desktop computer clients as source code. The source code is compiled on the client-side by Surge, a run-time environment distributed as a Web browser plug-in that lets users view Curl content. In order to meet everyone's needs, Curl is designed to interoperate with HTTP and standard server-side CGI scripts, and includes a SOAP implementation to connect to emerging Web services.
Critics predict that Curl's business model will not work. Right now, each Surge plug-in "reports" back to Curl Corporation and the developer pays Curl a fee based on the amount of code Surge executes. The "reporting" aspect of Curl is expected to raise privacy concerns for end-users and the pay-per-use billing model is expected to cause problems for developers who must work within a fixed budget.
At this time, Curl will only run on a Windows operating system, although Linux and Macintosh versions of Curl are currently being worked on. Curl's initial primary market is expected to be the corporate intranet.