All Thermodynamics

from HyperPhysics portal. This is rather a comprehensive online physics handbook containing "Thermodynamics" chapter. Site has a handle navigation, good illustrations, and very detail content.

http://hyperphysics.phy-astr.gsu.edu/hbase/heacon.html#heacon

Applied Thermodynamics

Definition and short explanations of terms, units and basic principles.

http://www.taftan.com/thermodynamics/

Basic Terms and Theory

from Engineers Edge. A definitions, short explanations and connection of basic thermodynamics terms.

http://www.engineersedge.com/thermodynamics/table_contents.htm

Computational Thermodynamics

Calculation of metal phase diagrams using the CALPHAD method. Also offers consulting services.

http://www.calphad.com/

Equation of State - Ideal Gas

Features equations describing the relationship between pressure, volume and pressure in gases. From NASA.

http://www.grc.nasa.gov/WWW/K-12/airplane/eqstat.html

Fundamentals of Thermodynamics

Lecture notes and problems from University of Pittsburg.

http://puccini.che.pitt.edu/~karlj/Classes/CHE2101/

Ideal Gas Law

Applet illustrating the ideal gas law : action of a piston in a pressure chamber filled with ideal gas.

http://jersey.uoregon.edu/vlab/Piston/index.html

Mass, Energy, and Freedom - The Coins of Thermodynamics

The basis for thermodynamics. An introduction to the conservation of energy, states of matter and changes of state.

http://web.mst.edu/~gbert/basic/thermo.html

Properties of Heat and Matter

Online book on Thermodynamics at UC Berkeley.

http://www.mip.berkeley.edu/physics/bookcdx.html

The Expert System For Thermodynamics

TEST is a visual environment to solve thermodynamics problems, pursue what-if scenarios and perform numerical experiments.

http://energy.sdsu.edu/testhome/

The Second Law of Thermodynamics by Frank L. Lambert

A qualitative introduction to the second law and entropy written for beginners in chemistry but useful for physics students too. Explains relationship with Murphy's Law.

http://secondlaw.oxy.edu/

Thermodynamics & Statistical Mechanics

Intermediate tutorial by Richard Fitzpatrick covers topics such as probability theory, heat and work, applications, and quantum statistics. From the University of Texas at Austin.

http://farside.ph.utexas.edu/teaching/sm1/lectures/lectures.html

Thermodynamics and Its Applications

Companion site to the textbook by J. W. Tester and M. Modell, includes answers to selected problems and current errata.

http://web.mit.edu/testerel/thermo/

Thermodynamics by Professor Z. S. Spakovszky

Basic thermodynamics course accompanied by lecture notes.

http://web.mit.edu/16.unified/www/FALL/thermodynamics/index.html