Closed platform

A closed platform, walled garden or closed ecosystem is a software system where the carrier or service provider has control over applications, content, and media, and restricts convenient access to non-approved applications or content. This is in contrast to an open platform, where consumers generally have unrestricted access to applications and content.

For example, in telecommunications, the services and applications accessible on a cell phone on any given wireless were formerly tightly controlled by the mobile operators. The operators limited the applications and developers that were available on users' home portals and home pages. Thus, a service provider might restrict user access to users whose account exhausted the pre-paid money on their account. This has long been a central issue constraining the telecommunications sector, as developers face huge hurdles in making their applications available to end-users.

In a more extreme example, with the pre-regulated 1970s American telephone system, Bell owned all the hardware (including all phones) and had indirect control over the information sent through their infrastructure. A landmark case was Hush-A-Phone v. United States, wherein Bell unsuccessfully sued a company producing plastic telephone attachments. In the case of Bell, it was an openly government sanctioned and regulated monopoly by the Communications Act of 1934.

More generally, a walled garden can refer to a closed or exclusive set of information services provided for users. Similar to a real walled garden, a user in a walled garden is unable to escape this area unless it is through the designated entry/exit points or the walls are removed.

An 2008 paper from the Harvard Business School differentiated a platform's openness/closedness by four aspects and gave example platforms.

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