This workshop aims at gathering the ALMA community to discuss and further develop the unique science that can be achieved at the highest frequencies offered (Bands 8, 9 and 10). ALMA is the only ground-based interferometer that can routinely observe at frequencies > 350 GHz, making it a truly unique instrument. At the workshop, we aim to discuss the status of high frequency observations for galactic and extragalactic science and to explore which questions have arisen in the field that can be answered with high frequency observations. We will also discuss future development, technologies, and the ALMA upgrade. The overall goal is to create new ideas, collaborations and synergies within our community and the observatory that will enhance the discovery space of ALMA.