BEAST is free.

http://www.beast2.org/

mrbayes is also free and good:

http://mrbayes.sourceforge.net

For a longer list of possible alternatives see:

http://en.wikipedia.org/wiki/List_of_phylogenetics_software

you can likewise go to http://evolution.genetics.washington.edu/phylip/software.html which gives you plenty of Information.

But there are already likewise plenty of web-based Tools offered, which you can usee freely, but the choice depends of what data you use (morphological or molecular).

e.g. TNT is often used for Parsimony analyses

see here

http://tnt.insectmuseum.org/index.php/Main_Page

Try MEGA6.0, Mr. Bayes, TNT, RaxML, Phylip, all are free