Interview with the lead researcher of the TAČR project Kateřina Jebava. The topic of the interview is the introduction of the multimedia web textbook Theatrum.online, which is the result of the project Theatrical Arts, Practices and Techniques as a Training Tool for Communication Skills and Civic, Social and Personal Competences - JAMUNI (TL05000128). The main research field of the project is the existing leisure program #buďjamák, which offers high school youth the opportunity to develop themselves in seminars, online lessons and creative workshops. The web-based textbook targets both educators and learners and functions as a simple website that has several levels of access. The textbook is not a comprehensive "explanation" of theatre, but offers four different ways of looking at this art form covered in the chapters Dialogue, Narrative, Mask, and Theatricality.