In 1502 he became one of two professors for mathematics (the other was Johannes Stabius, his friend from Ingolstadt[12]) at the Collegium poetarum et mathematicorum,[13] founded on Celtis' initiative by emperor Maximilian I the year before, as a part of the University of Vienna.
[16] As editor, Stiborius published an edition of Robert Grosseteste's Libellus Linconiensis de Phisicis lineis, angulis et figuris, per quas omnes acciones naturales complentur in 1503.
[18] In preparation of the 10th session of the 5th council of the Lateran, Pope Leo X requested in October 1514 from various rulers to have their scientists offer proposals on the calendar reform.
[19] Tanstetter and Stiborius's calendar reform proposal was published as Super requisitione sanctissimi Leonis Papae X. et divi Maximiliani Imp.
Aug. De Romani Calendarii correctione Consilium in Florentissimo studio Viennensi Anustriae conscriptum et aeditum ca.
He mentions a five-volume Opus Umbrarum ("Work of Shadows"), in which Stiborius treated various astronomical and mathematical topics such as cartographic projections, the theory and use of the astrolabe, including the saphea, the construction of sundials, and others.