BMIRT ToolKit is a suite of software containing BMIRT, LinkMIRT, SimuMIRT, and SimuMCAT. They are free to download for research purpose.To use a software, please fill the corresponding user agreement form and send it to me. Calibration software: BMIRTII(Yao, 2003, 2010), Bayesian Multivariate item Response Theory, is a computer program that uses Markov chain Monte Carlo (MCMC) Metropolics-Hastings method to produce item and ability parameter estimates and model fit statistics such as AIC, BIC, DIC, in multidimensional, multi-group item response theory model frame work; exploratory and confirmatory mode are supported; it supports three-parameter logistic model, generalized two-parameter partial-credit model, graded response model, higher-order model, testlet model, and rater model.