Apps similar to Howler.js include Amplitude.js, which is free and open source. Other options are SoundManager 2. Between them they cover the web and self-hosting.
Amplitude.js is a lightweight JavaScript library that allows you to control the design of your media controls in your webpage -- not the browser. No dependencies (jQuery not required).
SoundManager was written to meet a desire to have Javascript-driven sound for interactive web-based projects, and "to make it easy to play MP3s in the browser." It is free for use in both personal and commercial projects (see license, above.
