Crosslet is a free small (22k without dependencies) JavaScript widget for interactive visualisation and analysis of geostatistical datasets. You can also use it for visualizing and comparing multivariate datasets.
L. Salucci, D. Bonetta, S. Marr, and W. Binder. Proceedings of the 21st ACM SIGPLAN Symposium on Principles and Practice of Parallel Programming, page 40:1--40:2. ACM, (March 2016)
J. Merelo, A. Garc\'ıa, J. Laredo, J. Lupión, and F. Tricas. Proceedings of the 2007 GECCO conference companion on Genetic and evolutionary computation, page 2851--2858. New York, NY, USA, ACM, (2007)