Sure, in one sense Microsoft SharePoint is an application: the SharePoint software package is installed and deployed directly on a server (or cluster of multiple servers). But SharePoint is so much more than just another enterprise-level application. Fundamentally, SharePoint is also a platform. Beyond its ‘off-the-shelf’ capabilities for online collaboration and workflow management, SharePoint also serves as the backbone to enable specialized apps and solutions from third-party vendors.
With a SharePoint environment, you get a fully-featured platform upon which other business-critical applications can be installed. And under the broad umbrella of the SharePoint platform, there is a rich tapestry of business applications to choose from: Business Intelligence (BI) apps, content and document management apps and extensions, search software ‘bolt-ons’ including FAST Search Server, extensible code libraries, reusable web parts, security and compliance solutions and list goes on and on. While maybe SharePoint was originally conceived as a standalone program, it has evolved to become a premier applications platform for developers to customize and build upon.