The collection was made at the beginning of the century by a European project called COCONUT
Basically, it consists of links to other sources whcih have been classified towards:
Test Problems for Unconstrained (or Bound Constrained) Optimization
Test Problems for Constraint Satisfaction
Test Problems for Constrained Optimization
Test Problems for Combinatorial Optimization
Test Problems for Other Optimization Problems
Real Life Test Problems from Space Mission Design

Neumaier, A., Shcherbina, O., Huyer, W. et al. A comparison of complete global optimization solvers. Math. Program. 103, 335–356 (2005). https://doi.org/10.1007/s10107-005-0585-4

Eligius Hendrix

University of Malaga