The talk presented at FOSDEM conference in 2023 discussed the implementation of a solution called Kovasm, which allows for seamless editing of documents on Kolab online when the internet connection is lost. Rather than installing third-party software, Kovasm runs in the same sandbox as a web page with access only to what JavaScript can access. The tool uses WebAssembly, which is supported in most current browsers, and contains all the relevant C++ code of LibreOffice along with external libraries. The application structure is similar to iOS and Android apps with multiple threads communicating via web sockets. The talk also provided pointers for building the tool.