Urtext is an open-source library designed for those who prefer plaintext for writing, research, journaling, and personal organization. Users have highlighted its unique features like timestamp sorting, which enhances personal knowledge management significantly. Additionally, while it's praised for its capabilities as a Second Brain tool, it is noted that some familiarity with Sublime Text is required, and an ST license is essential for full functionality. This suggests a niche audience that might be tech-savvy yet tricky to onboard due to the learning curve involved with Sublime Text. Overall, Urtext stands out as a versatile option for users seeking to streamline their information management in a plaintext format.