Cumulus is "donation ware" not freeware or shareware. That is....you make a donation to the author. There are no trial periods or locked out features. You get a fully functional package. However, it is nice that you make a donation for the author's efforts. I think it is a very nice product that is easy to set up and provides features that many of the other software packages offer. Question is...why the Ambient only weather station ? Is it price versus the more expensive and expansive systems like the Davis Vue or Vantage Pro2 ?