Studies and applied works of structural analysis depend on specialized softwares and resources for 3D modeling. This article presents the results of a research that aimed to evaluate the effectiveness of version 2.1 of the Ester stereographic projection system for Structural Geology. The evaluation of the software involved tests with structural data of different geological contexts, submitted to graphic treatment in packages such as Stereonet, Stereonet9, QuickPlot, Dips, OpenStereo and other softwares accessible at low cost. The study privileged the truly free (open) softwares. One advance was the inclusion of the Tangent Polar Diagram into the Ester package. The tool helps to differentiate, in folded regions, conical folds from cylindrical folds. In the comparative evaluation, it was observed that diagrams produced by Ester 2.1 are similar to those generated by other programs. The advantage relates to resources that are not available in the other softwares analyzed. It is concluded that, in addition to resources heretofore unavailable, the tests showed good functionality. The experience signals new directions in the search for educational alternatives for teaching-learning in Structural Geology.Studies and applied works of structural analysis depend on specialized softwares and resources for 3D modeling. This article presents the results of a research that aimed to evaluate the effectiveness of version 2.1 of the Ester stereographic projection system for Structural Geology. The evaluation of the software involved tests with structural data of different geological contexts, submitted to graphic treatment in packages such as Stereonet, Stereonet9, QuickPlot, Dips, OpenStereo and other softwares accessible at low cost. The study privileged the truly free (open) softwares. One advance was the inclusion of the Tangent Polar Diagram into the Ester package. The tool helps to differentiate, in folded regions, conical folds from cylindrical folds. In the comparative evaluation, it was observed that diagrams produced by Ester 2.1 are similar to those generated by other programs. The advantage relates to resources that are not available in the other softwares analyzed. It is concluded that, in addition to resources heretofore unavailable, the tests showed good functionality. The experience signals new directions in the search for educational alternatives for teaching-learning in Structural Geology.