.DER file extension

The program works with the following extensions: jpg, wmf, bmp, png, gif, zip, jpeg, url, ivf, p7r, crd, cat, p7s, cer, tvp, cnf, prf, crl, qds, cdf, crt, rat, uea, der, shb, dib, shs, dun, sst, emf, stl, tif, jpe, udl, crds, ueaf, jfif, tiff, theme, msstyles, appref-ms and slupkg-ms

Professional Notepad is an advanced tool that allows you to view and edit HTML.

Belarc Advisor is a tool that can analyze your computer.

This is a development kit widely used for Server programming using Java platform.