JavaScript utility library for ECMAScript 5.1 (or higher, due to backwards compatibility). See the list of browsers supporting ES5 here.
jsu stands for and provides JavaScript Utilities. It targets older browser versions first unless there is a security risk, missing functionality or poor performance in newer browsers. Explicit support (dedicated code) is not planned for Internet Explorer as Microsoft Edge is its successor.
The features provided by jsu were originally part of the nvc project. Some of these features, such as type checking or timer events, are also available in other utility libraries. If these libraries are too large to include as dependencies, or if they rely on JavaScript versions that are too recent, you can use jsu as a possible fallback. For example, jsu_event.js supports generic and timer events in just a few lines of code. However, features like type checking are need-specific, because not all use cases accept a boolean object as a boolean, or a numeric string or an infinite number as a number; therefore, even jsu implementation might not be of any help in checking data types.
Overall, jsu is not a substitute for libraries such as jQuery or others with convenient functions like isEqual() performing deep comparison of arbitrary objects.
Documentation and examples are available here. Version changelog is here.
See this file for development and maintenance notes.