I think that in Dutch, the "ij" is actually a single letter, and I think it is actually equivalent to the letter "y"--it is actually acceptable to substitute "y" in place of "ij?????." In any case, in the United States when people talk about Edsger Dijkstra we usually pronounce the name as if it were spelled "Dykstra," with a long-I sound in the first syllable--exactly like the word "dike:" "dike-stra." I don't know how close this comes to the actual pronunciation in Dutch.

Yes Edsger Dijkstra

If Dutch is an option you may want to post it there. I'm guessing you're asking about Edsger Dijkstra?