Observed since 1998 recovery of the ozone layer likely caused by prohibiting some ozone-depleting substances under the Montreal Protocol may be unstable. Therefore the homogeneity of the ozone observations in comparison with data of previous decades continues to be important. The network of fully automated Brewer spectrophotometers operated since the earlier 1980s is one of the oldest global systems providing data for the ozone assessments. The existing software for control Brewer spectrophotometers was created more than 35 years ago and is in need of redeveloping to continue the long-term observations in the face of changing computer platforms. New cross-platform operating software for the Brewer is under development by a group of researchers from OIAP of RAS. The software is capable of running on computers with modern multitasking operating systems (Windows, Linux, macOS), and at the same time it has one codebase. In the new Brewer operating software, the Model/View architecture is implemented to separate the code of measurement data (models) from the code of rendering this data to the user or spectrophotometer (views). The model is responsible for data management and provides an interface for reading and writing this data, and the view retrieves the necessary data from the model, reacting to its changes, and sends the data to the user (or spectrophotometer), placing them properly in the GUI of application or into the serial port interface to which a spectrophotometer is connected. Models are developed in the C++ programming language using the cross-platform Qt framework, while the relational database SQLite is used as a persistent storage. The developed database of the new software for storing measurement data and instrumental constants consists of more than 30 tables and stores about 800 pieces of information. This software allows keeping the quality and uniformity of ozone and UV-radiation measurements on the Brewer spectrophotometers of the global ozone network.