Methods, systems, and computer program products for customizing content based on at least one operating characteristic of a mobile client. A mobile gateway receives content from a content source, such as an email server, a Web server, or some other content server. For example, content may include email, calendar, contact, task, Web, notification, financial, sports data, configuration information, etc. The mobile gateway customizes the content based on transforms assigned to each mobile client. Transforms account for differences in the software, display, processor, memory, communication channel, and the like, of each mobile client, without imposing additional processing burdens on the content server. Processing that is common among several transforms may be shared. Mobile clients may be any type of computer, including telephones, pagers, PDAs, laptops, and other mobile gateways.