Starry

Starry, designed by Yutaka Hara in 2008 for his book, Rubyで作る奇妙なプログラミング言語, is a stack-based esoteric programming language. The book discusses the implementation of esolangs in Ruby; Starry is used as an example language.

Syntax
The only meaningful characters are space and  -- all other characters are ignored. Each sequence of spaces followed by non-space character represents a single instruction.

Computational class
Stack values are unbounded; using the swap, add, subtract, label, and "branch if non-zero" instructions, conversion from a 2-register Minsky machine is trivial. Therefore, Starry is Turing complete.

Hello, world!
+              +  *       +      * + .        +              +  *       +      *     * + .            +     * + . + .         +     * + .              +            +   *         +     * * + .                 + *  + .              + +  *           +     *      * + .             + * + .        +     *  + .           + * + .             + * + .               +            +  *         +     *  * +.

Fibonacci numbers
+     + ` +   +     * +   .               + . + ' Disassembled: push, 0], [:push, 1],  [:label, 1],  [:dup],  [:rotate],  [:+],  [:dup],  [:num_out],  [:push, 10],  [:char_out],  [:dup],  [:jump, 1

External resources

 * Ruby implementation from the book on GitHub