Microsoft has withdrawn a patent application for “Object Test Bench” in
Visual Studio. The functionality in Visual Studio had been incorporated
into the product
without attribution to BlueJ or its creator. Microsoft had then
patent application for the same.
BlueJ is a free integrated Java environment specifically designed for introductory teaching. It was developed for the purpose of teaching object orientation with Java. .Object Test Bench in Visual Studio was similar to the functionality in BlueJ.
Michael Kölling, one of the designers of BlueJ, in his blog says