1. Orthogonal Designs Wolf Holzmann, Hadi Kharaghani
   
   • There are all weighing matrices of order 40 and 56

2. The L-functions and modular forms database (LMFDB)

3. Complex Hadamard Matrices catalog pages maintained by Bruzda, Tadej, Zyczkowski et al

4. Butson Home, maintained by Lampio, Szollosi, Ostergard

5. Dan Gordon’s databases, giving Covering Designs, Difference Sets, Circulant Weighing Matrices,Steiner Systems

6. N. J. A. Sloane’s Library of Hadamard matrices, giving all equivalence classes up to order 28

7. Jeff Dinitz’ maintained page of New results (post- second edition of the CRC Handbook) for Section 5, which includes Hadamard matrices and Orthogonal Designs

8. Encyclopedia of Design Theory, by Peter Cameron

9. Atlas of Weighing Matrices (AWM)

10. Frank Ruskey’s Combinatorial Object Server

11. Code Tables archive by Marcus Grassl

    Code Tables archive by Marcus Grassl

12. MinT, the online database for optimal parameters of (t, m, s)-nets, (t, s)-sequences, orthogonal arrays, linear codes, and OOAs

13.  Jennifer Seberry's site at Nickolay Balonin's Leonard Euler Net mathscinet.ru

14. web archive of Jennifer Seberry's papers

15. Jennifer Seberry’s Home Page, with links to archived Hadamard matrices,Williamson Matrices, Good Matrices, Inequivalence Results, Weighing Matrices and Sequences, SBIBD, D-optimal designs, Almost Good Matrices (and other stuff)

16. Christos Koukouvinos’ Design Theory directory, miscellaneous objects connected to this field

17. OpenDreamKit: a European program that ended in 2019

18. MaRDI: Mathematical Research Data Initiative: a German data infrastructure program

19. MathDataHub

20. International Mathematical Knowledge Trust

	First Created: October 2021
	Last Updated: October 2021