adj. A form of rap music with lyrics relating to computers, technology, and engineering.
Rajeev Bajaj, a Silicon Valley entrepreneur, was a geeksta pioneer, according to the Times of India. His "Geek Rhythms" debut album includes these lyrics:

"Hot electrons can ruin my day

"Switch the transistor to go the other way

"I make my software self-healing

"To prevent such a calamity from dealing

"A deadly blow to my directory root

"If all else fails…… YO, REBOOT!"
—Alex Cruden, “Five things about geeksta rap,” Detroit Free Press, December 27, 2006
Tupac and Biggie, move over. A new hip-hop feud is brewing that glamorizes not guns and 'hos but Java and secure encryption algorithms.

While gangsta rap is seen as celebrating the violence and aggression that claimed two of its brightest stars, "geeksta" rap is a hip-hop genre celebrating coding skills and school grades.

Also dubbed "nerdcore," this branch of hip-hop is for geeks, by geeks. Geeksta rappers adopt the same combative verbal-assault stylings of their forerunners, but bust rhymes about elite script compiling and dope machine code.
—Robert Andrews, “Rap Marketing Comes to Nerdcore,” Wired, June 23, 2005
2003 (earliest)
Science education and outreach efforts must compete for the attention of students in an environment filled with many distractions. Many of the most compelling of these distractions arise from popular culture. Rather than bemoaning this situation, we propose that we make use of some of those elements of popular culture which garner the most attention. In particular, we propose that we utilize the popularity of current hip-hop and rap music in science education and outreach efforts. To that end, we present some examples of what we call 'geeksta rap' and discuss some of the considerations relevant for its preparation. We also discuss various uses of 'geeksta rap' in science education and outreach.
—F. Hall, “Geeksta Rap: An Example of the Utilization of Elements of Popular Culture in Science Education and Outreach,” American Geophysical Union, December 01, 2003
The sound of Riverside's Voodoo Glow Skulls, a combination of aggressive punk rock and upbeat ska, has often been described as "nerdcore" due to the band's appearance. Most of its members wear glasses.
—Kenneth L. Stansbury, “To do that Voodoo they do so well,” Press Enterprise, July 31, 1994