Software from Marimba, Inc. of Mountain View, CA (www.marimba.com) that helps administrators install and update applications and information across a network. For example, if a number of users on a network use a version of Microsoft Word that's been recently updated, the administrator can use Castanet to update the users' versions without physically installing each new package. Castanet will examine the old and the new versions, identify differences (a process called differencing), and send the changes to each user. Castenet uses channels, usually containing one kind of application, to send information to users, who receive them with a desktop application called a tuner. Administrators control content at the back-end with a transmitter.