POSIX Threads Explained, Part 1  
   How to use POSIX threads to increase the responsiveness and performance of your code.
   http://www-106.ibm.com/developerworks/library/posix1.html

Getting Started with POSIX Threads  
   Introduction to POSIX threads with sample source available for download.
   http://dis.cs.umass.edu/~wagner/threads_html/tutorial.html

Introduction to Programming Threads  
   Introduces what threads are, why they are useful and how to program with them using the POSIX 1003.1c thread standard and API bindings for C.
   http://www.mit.edu/people/proven/IAP_2000/index.html

Next Generation POSIX Threading: NGPT  
   Goals: solve problems of pthreads library on Linux; add M:N threading, raise POSIX compliance and speed in threaded programs, more so under SMP, give threading services more like commercial Unix. Derived from GNU Pth. [Open Source, LGPL]
   http://www-124.ibm.com/pthreads/

LinuxThreads FAQ  
   Frequently asked questions about the kernel-level multi-threading library for Linux.
   http://pauillac.inria.fr/~xleroy/linuxthreads/faq.html

GNU Pth  
   Portable Threads: portable POSIX/ANSI-C library for Unix gives non-preemptive priority-based scheduling for multithreading in programs. All threads run in same address space, each has its own program counter, run time stack, signal mask, errno variable; c
   http://www.gnu.org/software/pth/

Native POSIX Thread Library (NPTL) 0.1 Released  
   Initial performance: 8x Linux Threads, 4x NGPT. [Linux Weekly News]
   http://lwn.net/Articles/10465/

Native POSIX Thread Library: NPTL  
   White paper describes actual implementation of thread library for which requirements are spelled out in a prior document. Many things are different. [Red Hat, PDF]
   http://people.redhat.com/drepper/nptl-design.pdf

POSIX Threads Explained, Part 2  
   How to protect the integrity of shared data structures in threaded code by using mutexes.
   http://www-106.ibm.com/developerworks/library/l-posix2/

Multithreaded Programming with Pthreads  
   The complimentary site for the book with the same title.
   http://vig.prenhall.com/catalog/professional/product/1,4096,0136807291,00.html

POSIX Threads Explained, Part 3  
   How to use condition variables.
   http://www-106.ibm.com/developerworks/library/l-posix3/

POSIX Threads Tutorial  
   How to write parallel applications using POSIX threads. By Mark Hays.
   http://www.laptev.org/doc/pthreads.html

An Introduction to POSIX Threads  
   This article demystifies the POSIX thread interface, providing practical examples of threaded code for consideration.
   http://www-106.ibm.com/developerworks/library/l-pthred.html

POSIX Synchronous Wrappers  
   A set of C++ wrappers for posix synchronous entities such as pthread, mutexes and condition.
   http://www.partow.net/programming/posixsynchwrapper/index.html

Multi-Threaded Programming with POSIX Threads  
   Attempts to show how the library's features can be used in "real-life" programs. It explains the different tools defined by the library, shows how to use them, and then gives an example of using them to solve programming problems.
   http://users.actcom.co.il/~choo/lupg/tutorials/multi-thread/multi-thread.html

POSIX Threads Programming  
   Provides an overview of threads programming and the POSIX threads API.
   http://www.llnl.gov/computing/tutorials/workshops/workshop/pthreads/MAIN.html