Mplus is described as 'statistical modeling program that provides researchers with a flexible tool to analyze their data' and is a Statistical Analyzer in the Education & Reference category. There are more than 10 alternatives to Mplus for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and BSD. The best alternative is R (programming language), which is both free and Open Source. Other great apps like Mplus are RStudio (Free, Open Source), PSPP (Free, Open Source), RKWard (Free, Open Source) and IBM SPSS Statistics (Paid).
PSPP is a free software application for analysis of sampled data. It has a graphical user interface and conventional command line interface. It is written in C, uses GNU Scientific Library for its mathematical routines, and plotutils for generating graphs.
The IBM SPSS software platform offers advanced statistical analysis, a vast library of machine-learning algorithms, text analysis, open-source extensibility, integration with big data and seamless deployment into applications.
SOFA Statistics is an open-source statistical package, with an emphasis on ease of use, learn as you go, and beautiful output. The name stands for Statistics Open For All. It has a graphical user interface and can connect directly to MySQL, SQLite, MS Access, and MS SQL Server.