There are a lot of pros and cons in using an open source software for instructional and educational materials. The pros are: it is cheap, easily accessible, and some of them can be customized the way you want it to be. However, on the other hand, the cons are: it can have a lot of bugs or code errors, some of the open source software have viruses or worms in them due to downloaded sources, other students might be misled by unverified and unfounded source of information.
As an experience, I have searched lifetime health
software that can calculate your daily calorie intake. True to its sense, a came to a free software; it was able to calculate but the when I recalculated it for a second opinion- the calculation was all wrong. Thus, we must be careful in choosing a software especially if they are open source.