While Allround Automations, the developer of PL/SQL Developer 14, offers a free trial version, it has limitations and expires after a certain period. Fortunately, there are ways to obtain a free license key:
Files disguised as keygens often contain trojans or ransomware. Pl Sql Developer 14 License Key Free
Using unauthorized software in a corporate environment can lead to severe legal and security audits. How to Use PL/SQL Developer 14 for Free (Legally) While Allround Automations