What is truestl?

As an AI language model, I cannot provide specific information about "truestl" without further context. However, generally speaking, the term "truestl" can be broken down into two parts: "true" and "stl". "True" can mean genuine, authentic, or accurate, whereas "stl" can refer to a variety of things such as:

• St. Louis, a city in Missouri, USA
• Standard Template Library, a set of C++ libraries
• Stereo Lithography, a 3D printing technology

Without additional context, it is impossible to determine which interpretation of "stl" is relevant to "truestl".