The reason techies around the world contribute to the “open source” environments is that they build smaller pieces of software that function with your galaxy, and they hope to charge you for that functionality. Each category has many choices (i.e. a calendar or clock for your site), and many of them are rated. There are free ones and commercial ones. If you see an unrated free one, chances are some aspiring software genius has created something, and he is hoping you will help him test it. The rated free ones often work perfectly well, and many good ratings can give you confidence in your selection. The commercial ones normally are endorsed in the sense that people have paid good money to use them.