Primer Dimer / Hairpin Algorithms
It is important visualize more faces to design primer or oligo and PCR experiments:

- calculate thermodynamic parameters of DNA Hybridization (Oligo/Template)


compute hairpin-loop, dimer, bases penality and melting temperature about primer or pair primer
calculate statistics about melting temperature with the change in composition and mix PCR concentration


with google you could find more tools but you must choose a tool of a sequencing team.
almost all tools use mfold algorithm, it's simple and effective:

M. Zuker, D. H. Mathews &amp; D. H. Turner. Algorithms and Thermodynamics for RNA Secondary Structure Prediction: A Practical Guide In A Biochemistry and Biotechnology, 11-43, J. Barciszewski and B. F. C. Clark, eds. , NATO ASI Series, Kluwer Academic Publishers, Dordrecht, NL, 1999.

I worked in a sequencing team and there was a programmer. he developed a fantastic tools. he is a little english, but he could support you: http://promix.cribi.unipd.it/cgi-bin/promix/melting/melting_main.exe