Version Control in 6.1 beta release :

Developer Collaboration combined with the integrated file version control makes the NetBeans IDE a powerful tool for your distributed development team.

Integrated Version Control Tools The IDE recognizes your existing version-controlled directories automatically. Context menus allow you to quickly update, check out, compare (diff), and rename files, and commit modifications. CVS, Subversion, Mercurial* Choose between the three most popular version control systems: CVS, Subversion or Mercurial. The Subversion implementation supports file, http, https, svn, and svn+ssh authentication protocols. The CVS implementation supports pserver, ext, local and fork authentication protocols. (*) A Mercurial plugin is available from the Plugin Manager (Tools > Plugins). File Status and History Use the Versioning window to see all recent changes in a directory with one glance. Badges and colors on file names inform you about the file status. Get a quick overview of each file's history, read commit log messages, and roll back changes to previous versions if necessary.
Line-Based Diff Viewer New, removed, and modified lines are clearly color-coded in the Editor's left sidebar, and quick navigation marks are placed in the errorstripe to the right. Clicking on the left sidebar allows you to roll back individual changes, or to open the Diff Viewer. Use the Diff Viewer to compare two files side by side, line by line, if immediate and transparent conflict resolution is necessary. The Diff viewer includes a full-featured editor pane so you can resolve merge conflicts in the current file in an intuitive way.
Remote Project Sharing With the Developer Collaboration plugin* you share NetBeans projects in real time over the network. You can review your partners' work, or allow them to make remote changes to your project: All invited parties are able to compile, debug, profile, and run the shared application, and you can watch each other make changes to the source code. Developer Collaboration Chat Discuss source code in style with remote developers: The Developer Collaboration plugin* allows you to send instant messages in plain text, XML, HTML, or Java, complete with syntax highlighting.