The development system we use in the office has changed quite a bit from what we distributed in Third Edition, and we continue to extend and improve it. Inferno's Fourth Edition is released as source updates on Google Code, and as periodic snapshots, both taken from the development system in the office.

Here is a list of many of the things that changed between Third and Fourth editions (there have been many others, major and minor, since then). Each item often is a link to a page that that gives more detail about it.

• New licence terms (a `dual licence' scheme allowing use as Free Software)
• Styx revision based on 9P2000, and consequent changes to Sys
• Authentication changes
• Improved colour graphics support, including compositing
• Scalable fonts using Freetype
• Revamped Tk implementation
• Window management moved out of Tk to a separate window manager in Limbo
• Limbo: exception handling and fixed-point
• Limbo: other possible changes
• Dis VM changes
• More commands and library modules
• Better network service configuration
• /net/dns served by host and native DNS resolver
• Hosted kernels configured from a parts list as for native kernels
• Signed modules
• Internet Explorer plug-in revised and in source form
• Expanded documentation

A short document gives a survey of current system and interface changes. (It is itself being revised as things change.)

9 March 2008