OffSec, formerly Offensive Security, is the creator of Kali Linux and the OSCP — arguably the most respected entry-to-mid-level penetration testing certification.
Learning is fully online and self-paced, structured around extensive lab environments where students compromise real machines. Certifications are earned through rigorous, hands-on practical exams rather than multiple-choice tests.
The Learn One and Learn Unlimited subscriptions bundle course materials, lab time and exam attempts. Ideal for self-driven learners targeting offensive security and red-team roles.