School director Dr Elaine Webster, who is also the university's director of continuing education, said the school had initially operated on a trial basis but had long since established itself as a "really important" national institution.
The school was this year offering 73 papers, up from 68 last year.
Among latest offerings were 14 new papers, including on bioethics and film, as well as on social media and online communities, and a theatre studies paper on improvisation, the latter being offered in Auckland.
As of Friday, 34 papers were full. About 2270 domestic, expected to reduce somewhat over the next few days, and 175 overseas enrolments had been received. Nearly 2240 enrolments were received last year, and the overall outcome was likely to be similar this year.
"People just love summer school."
This was a "fantastic" institution and had a "really nice energy" about it, she said.
Students can gain credit for courses with six weeks of study, instead of about 13 weeks usually required to complete equivalent papers during the main university study year.
In 2009, the school offered 80 papers and attracted a record 2639 enrolments, but the university has since had to impose continuing restrictions to avoid carrying too many students beyond the funding level agreed with the Tertiary Education Commission.
Dr Webster said the school was a boost for Dunedin's economy in a traditionally quiet time of the year.
Some students also enjoyed the somewhat more intimate feeling of studying when there were fewer people about.
Some people were taking papers to enable them to complete their overall studies more quickly, while other students enjoyed trying subjects they might not usually take.
Dr Webster recently succeeded Dr Claire Matthewson as director of the summer school and continuing education.
