Oscar Moreno de Ayala, PhD was my thesis advisor and mentor. He passed away in 2015, and his colleagues described him as "the spirit of mathematics in Puerto Rico". And while that is true, I think it misses out on the impact Oscar had on computer science in Puerto Rico.
The mathematics genealogy project lists two students for Oscar, José Ortiz-Ubarri and myself, and we're both computer scientists. That's a lower bound on his impact, but Oscar trained many more students, serving on committees, or as employer or master's advisor. In my computer science department, besides José and me, Oscar worked with Carlos Corrada, Edusmildo Orozco, Ivelisse Rubio.
Oscar and Heralal Janwa were in the proposal that established the PhD program in computer and information science and enginnering at UPR-Mayagüez. In fact, Oscar was instrumental in obtaining the awards for NSFNet that brought Internet to Puerto Rico, and the Internet2 award. He also brought several parallel systems including an Alliant, an Intel Paragon, and a Cray, leading up to the establishment of the UPR High Performance Computing facility by Guy Cormier, where I have worked since 2000.
Oscar also managed the .pr top level domain for many years, albeit with a controversy when he moved the administration from the UPR to an external entity.
In fact, controversy and conflict surrounded Oscar. He was very hard to get along with. Everyone has stories with Oscar. I'll share one.
When we moved back to Puerto Rico in the late '90s I was working with Rosemarie Plaetke on software for genetic and radiation hybrid mapping. Rosie was applying for a grant, and asked me to identify a mentor in Puerto Rico she could subcontract so I could continue on the project. Oscar was a friend of the family*, so I asked him if he could serve as my mentor. He said no! A number of years later he got interested in cDNA microarrays, and found some presentations I had made on gene expresison clustering and networks, he called me up and asked me to meet with him to discuss microarrays. That eventually grew into my PhD project.
Warts and all, I think the entire CS community in Puerto Rico owes Moreno a great deal, and I cerrtainly owe him my career as a professor of computer science. I miss him, even though I sometimes dreaded our conversations.
* Oscar studied with my aunt Elsa. She claimed she got thrown out of class one day because Oscar kept talking during class. I asked him one day, and he clamied the professor threw them out because my aunt was talking.