The licensing is a bit complicated. It is not really open source, until later, when it is:
"∙ Free for non-commercial and educational use."
"∙ Commercial use requires the purchase of a license."
and then
"Because of the support we've received from open source communities, we've decided to dual-license the code after 18 months - every commit, starting with 017c513, will be dual-licensed via the MIT License 18 months from that commit's date to master."
"∙ Free for non-commercial and educational use."
"∙ Commercial use requires the purchase of a license."
and then
"Because of the support we've received from open source communities, we've decided to dual-license the code after 18 months - every commit, starting with 017c513, will be dual-licensed via the MIT License 18 months from that commit's date to master."