Historical question

Hi All, I am writing a paper on some C language code I have written that does FOCE. I want to write a few sentences about the history of NONMEM but I'm not 100% sure it is correct. Can someone knowledgeable give me some feedback on this? "NONMEM software was developed at USCF in the late 1970s and became the de-facto industry standard when the first-order-conditional estimation with interaction (FOCE-I) method reaching wide use in the field. NONMEM was open source until version 5 when the rights were obtained by Icon PLC and it became encrypted-source. The investment of Icon PLC has resulted in considerable NONMEM development with many bug-fixes and new features available in current version 7.5.1. " Warm regards, Douglas Eleveld ________________________________