Toolbox Coding is a sole proprietorship (aka Aaron Todd Sherrill). Toolbox Coding develops software to support the learning of Mandarin Chinese. The flagship product, Chinese Toolbox, is now in its third iteration. Chinese Toolbox FREE was first introduced in 2007. In 2009, Chinese Toolbox FREE was updated, and a new product, Chinese Toolbox READER, was introduced. The 2011 release of Chinese Toolbox combines the two previous products. A mode paradigm is used to distinguish between free and paid features. In FREE mode, Chinese Toolbox is free to use indefinitely. It support mainly character-oriented reading. READER mode provides full support for all of the newest and most advanced features of Chinese Toolbox.