A MAJOR weapon in combating the transmission of Covid-19 is contact tracing. In March 2020, Singapore launched TraceTogether - the world's first consent-based contact tracing app which utilises a privacy preserving protocol to anonymise and encrypt BlueTooth proximity data shared between mobile phones running the app.

Over a million people have since installed the TraceTogether app on their devices and joined the fight to protect Singapore from the spread of Covid-19. To support the international community's battle against the pandemic, the republic also open-sourced TraceTogether by making its codebase freely available to anyone in the world to adapt and use. It is heartening to note that the open-sourced codebase has contributed to Australia's development of its own contact tracing COVIDSafe app. This is testament to the ability of open source software (OSS) to foster cross-border collaborations and fast-track digital innovations for the public good.

Although there is growing awareness of OSS, many still wonder what it encompasses. In essence, OSS refers to software source codes made freely available by their developers under any open source licence (OSL) which grants a number of principal freedoms - the freedom to use, the freedom to copy, freedom to modify and freedom to distribute. Unlike object sources which are machine-readable strings of binary 0s and 1s, source codes are human-readable lines of programming text which allow developers to not only study and understand how the software works but also to customise and modify it to suit their specific needs.