BATE pH calculator
BATE calculates pH of solutions containing mixtures of acid and base with up to 4 dissociation steps and titration curves for these acids and bases. Ionic strentgh can be calculated from the dissociated forms concentrations, omitted or forced upon the solution. ... Program contains editable database of common weak acids and bases and accepts acid and base dissociation constants and protonation constants as input, calculating all other types of constants as needed. ... Extensive tutorial and help.
http://www.chembuddy.com/files/BATEInstall.exe - 363Kb - Download - Screenshot

CurTiPot Acid-Base pH and Titration
CurTiPot is a powerful all-in-one freeware for acid-base equilibria calculations such as pH of aqueous solutions, dissociation degree of weak and polyprotic systems, pKa determinations, simulation of titration curves and analysis of real titration data with chemometric tools like interpolation,... - Generation of protonation diagrams and distribution curves of the equilibrium species of acids and bases as a function of pH or of added volume of titrant. ... xls file. ... Simply unzip, open with Microsoft Excel (at medium security level), activate macros and start learning and working.
http://www2.iq.usp.br/docente/gutz/curtipot/curtipot_.zip - 305Kb - Download - Screenshot