Lavaan

lavaan is an open-source structural equation modeling (SEM) package for the statistical programming language R. Created by Yves Rosseel in 2010, lavaan is intended to be a free open-source commercial-quality alternative to commercial (SEM) software packages such as Mplus or IBM SPSS Amos.

Comparison with other SEM packages

A variety of open-source, free, and commercial structural equation modeling software packages are available besides lavaan, such as Amos, SAS PROC CALIS, R package sem, OpenMx, LISREL, EQS, and Mplus. The main difference between packages is the presence of a graphical interface for model specification and presentation of results. Each package differs in terms of its strengths and weaknesses. lavaan was shown to be feature equivalent to commercial packages, with a compact scripting capability even for complex models as a key strength, and the ability to mimic Mplus and EQS results as a special feature.

Impact

After 15 years of being developed, lavaan has become one of the standard structural equation modeling software package of choice for many researchers and data scientists across the world; evidenced in its use in studies, part of software reviews, and published books. It was downloaded more than 4 million times to date.