The original curriculum was composed with the help from acclaimed university professors Svetozar Kurepa, Branislav Marković and Vladimir Devide.

The newly founded school was named Education Center for Mathematics and Computer Science (Matematičko informatički obrazovni centar), abbreviated as MIOC.

In 2007, the management of the school planned to hold a celebration of its thirty years of existence which sparked strong protests from alumni who graduated before 1977.

With an increased number of classrooms, the classes now take place only in the morning while afternoons are reserved for extracurricular activities, a relative rarity among Croatian schools.

In the national program, the students follow the curriculum of mathematical - natural scientific gymnasium, as outlined by the Ministry of Science, Education and Sports (Ministarstvo znanosti, obrazovanja i športa).

[5] The International Baccalaureate program, implemented at the school in 1991, is not publicly funded but is instead financed by student tuitions.

Besides cooperating with many governmental and non-governmental organizations dealing with education in Zagreb, the school is noted for its long-standing friendship with Second Gymnasium (II.

There are many alumni working at aforementioned faculties ranging from teaching assistants to academics, such as Marko Tadić, a professor at the Department of Mathematics.

Branko Jeren, who was the Minister of Science and Technology of Croatia in the mid-nineties, who is also currently a professor at Faculty of Electrical Engineering and Computing, is also an alumnus of the school.

Perhaps the most notable scientist who graduated from MIOC is Marin Soljačić, a physicist currently residing in the United States.

Besides Denis Kuljiš, a known political columnist and reporter from Zagreb, some national TV personalities and actors also graduated from Fifteenth Gymnasium.

Examples include Filip Brajković, Amar Bukvić (who graduated in the International Baccalaureate program)[17] and Domagoj Novokmet, who acted as a host for the celebration of the school held in 2007 in Vatroslav Lisinski Concert Hall.