Pi Filter Designer is a free, open-source software toolkit for designing and simulating passive filters with arbitrary order, cut-off frequency and filter type.
LAStools is a suite of open-source tools for the processing of airborne, mobile, and terrestrial laser scanning point clouds and for creating 3D terrain and surface models.
Pixio Free Photo Editor is a powerful and easy-to-use photo editing tool that allows you to quickly and easily enhance your photos with a variety of tools, filters, and effects.
