What language used orthogonality as a primary design criterion?
Language that used orthogonality as a primary design criterion is ALGOL 68. The main aims and principles of design of ALGOL 68 :
1. Completeness and clarity of design
2. Orthogonal design
3. Security
4. Efficiency : Static mode checking, mode-independent parsing, Independent compilation, Loop optimization, representations – in minimal & larger character sets.