Add spaces: Butnon-copyleftedfreesoftwarealsoexists.Webelievethereareimportantreasonswhyitisbettertousecopyleft,butifyourprogramisnon-copyleftedfreesoftware,wecanstilluseit.
But non-copylefted free software also exists. We believe there are important reasons why it is better to use copyleft, but if your program is non-copylefted free software, we can still use it.