S.org
Scrum.org
Rigorous Scrum certifications without mandatory training
PSM I requires 85% to pass — higher bar than CSM
Scrum.org was founded by Scrum co-creator Ken Schwaber and offers the Professional Scrum Master (PSM) series. Unlike Scrum Alliance, Scrum.org certs require no paid course — you can self-study and sit the exam for $200.