With this release, implemented commands mainly cls to clear the console screen and play-file to play a music file.
And, removed command only-number, because regex command can substitute it.
All changes: 1.11...1.12

With this release, implemented mainly object-oriented system etc. So, it became can define original data structure.
All changes: 1.10...1.11

With this release, implemented Trigonometric function and enhance memory's variable view.
All changes: 1.9...1.10

With this release, the Stack programming language now supports regular expression processing.
All changes: 1.8...1.9

With this release, you can now connect to file systems using data structures in the Stack programming language.
All changes: 1.7...1.8

In this release, it is now possible to collaborate with external entities, such as the command request that sends an HTTP request and the command open that opens a file.
All changes: 1.6...1.7

In this release, the REPL now supports multi-line input and multi-thread processing.
All changes: 1.5...1.6

This release implements things like the cast command that allows explicit type conversion to the Stack programming language.
All changes: 1.4...1.5