The present invention pertains generally to the field of therapeutic compounds for treating proliferative disorders, cancer, etc., and more specifically to certain pyrido[2,3-b]pyrazin-8-substituted compounds, as described herein, which, inter alia, inhibit RAF (e.g.,B-RAF) activity. The present invention also pertains to pharmaceutical compositions comprising such compounds, and the use of such compounds and compositions, both in vitro and in vivo, to inhibit RAF (e.g., BRAF) activity, to inhibit receptor tyrosine kinase (RTK) activity, to inhibit cell proliferation, and in the treatment of diseases and disorders that are ameliorated by the inhibition of RAF, RTK, etc., proliferative disorders such as cancer (e.g., colorectal cancer, melanoma), etc.