Ooh, several of those as well! Sibling comment mentions Radia Perlman. She invented Spanning Tree Protocol (STP) which prevents loops in wiring from taking down networks. (Plug an Ethernet cable into the same switch it comes out of.) This has saved everyone's bacon countless times. Elizabeth Feinler managed hostnames before there was DNS and helped establish several of the top level domains (TLD)s we use today. There's Karen Spärck Jones without whom, search engines wouldn't be what they are today. Judy Estrin helped with TCP/IP, Sally Floyd worked on congestion control algorithms, without which, the Internet would have gotten all choked up and never gotten off the ground. Susan Estrada helped commercialize the Internet, with her work on internet exchanges (IX), and Jean Armour Polly gets credit for coining the phrase "surfing the Internet." but should be better known for pioneering public Internet access and for her work with families and kids getting online.

These women played a critical role in creating the Internet we have today.

Radia Perlman is the name that jumps to mind for me, but there are a bunch of others.

DoD