Nios

ECE 576 Advanced Microcontroller Systems on a Programmable Chip
Course on system-on-chip and embedded control; much Nios information; taught by Bruce Land, staff member in Neurobiology and Behavior and Electrical and Computer Engineering, Cornell University.
http://instruct1.cit.cornell.edu/courses/ece576/

ixo.de: Kolja Waschk
Projects to port (add support for) Altera NIOS II processor to 2 realtime operating systems: FreeRTOS, RTEMS; descriptions, documents, downloads.
http://www.ixo.de/

Nios Community Forum
News, forum, marketplace, projects, support, communication, and idea sharing, for embedded processor development.
http://www.niosforum.com/

Nios Community Wiki
Dedicated to making the most of Nios II embedded processor development by giving a means to collaborate on user guides, design tips, and other frequently asked questions. WikiHome, JotSpot Wiki.
http://nioswiki.jot.com/WikiHome

Nios Embedded Processor
Product page on general-purpose RISC CPU implemented as soft core in FPGAs; had 16-bit and 32-bit CPUs; documents, data, diagrams. Altera Corp.
http://www.altera.com/products/ip/processors/nios/nio-index.html

Nios II
Growing article, with links to many related topics. Wikipedia.
http://en.wikipedia.org/wiki/Nios_II