Carto, the platform for making online maps, recently abandoned it's free license option. The reason they gave was that many users were creating accounts, sometimes several accounts, and simply not using them. This became expensive overhead for them to manage. As a result they now offer a Professional or Enterprise plan once your free trial expires. This new pricing scheme is shown below:
Note that non-profit organizations receive a 20% discount off this Professional license. This license also affords you many more benefits than the previous free license. For example, the free license gave you 50Mb of cloud storage space while the Professional plan gives you 500Mb. It also allows you to set permissions on your datasets to make them private. It also gives you email and online support.If that price is beyond your organizations budget you will notice that directly below the pricing plan is a section covering FREE Plans for Students and Great Causes! 
Carto has a grant program. You can read about this program here. All it takes to apply is filling out an application form!