1. Scribe It's designed to pair programs such as Salesforce and Microsoft Dynamics, but it can be jiggered to pair others.
    Price: $4,000 and up, depending on which programs you want to link
  2. DataSync This open-source application links up other open-source applications (such as Zimbra and Joomla) so that you can access them all with a single sign-on.
    Price: Free to download, and up to about $40 a month per user for a hosted version with tech support
  3. Jitterbit This open-source program, which has a drag-and-drop interface, is ready-made to merge a variety of programs and databases.
    Price: Free to download, $10,000 a year and up for tech support
  4. Microsoft BizTalk Server This software for servers can hook up large enterprise applications. It plays well with other Microsoft offerings such as Office and SharePoint.
    Price: $8,499 for the standard version, $34,999 for the enterprise version
  5. SnapLogic This open-source program is designed to connect Web-based applications, like Salesforce, to other Web-based or desktop applications.
    Price: Free to download, $7,500 a year and up for support