Celebrating two decades of global scientific computing

Imagine a planetary computer capable of storing and processing hundreds of petabytes of data for the research needs of a worldwide community of scientists. This is the Worldwide LHC Computing Grid (WLCG), which is celebrating its 20th anniversary.

Originally conceived to handle the unprecedented data volumes of the Large Hadron Collider (LHC), the WLCG has evolved into a global network connecting hundreds of computing centres across more than 40 countries. It enables thousands of scientists worldwide to store, process and analyse massive amounts of data in quasi-real time, supporting discoveries in particle physics.

On 8 December, a special event at the CERN Science Gateway brought together the international community that has turned this ambitious project into one of the largest distributed computing collaborations in the world. Key figures from the project highlighted its history, challenges and future prospects. Les Robertson, whose efforts and leadership were instrumental during the early days of the Grid, reflected on how the idea was born and the challenges of building something that had never been done before. It was an ambitious idea for its time, one that required both technological innovation and unprecedented cooperation across countries. Yet this early confidence proved justified: the Grid rapidly moved from concept to reality, paving the way for a new model of large-scale scientific computing.

For the Academia Sinica Grid Centre in Taipei, for example, joining the WLCG collaboration had a profound impact. After becoming the first WLCG Tier 1 centre, the institute quickly grew into a hub for knowledge sharing across Asia and Europe. It helped build expertise in distributed computing and networking while supporting other regional institutions in joining the global effort. According to Simon Lin, former Director of the Academia Sinica Grid Centre, the true achievement was not technological but human: by bringing together scientists from across Asia and Europe, the project fostered a community united by shared knowledge and a common purpose.

Its collaborative model is the core of the WLCG's success. The WLCG infrastructure manages vast volumes of LHC data, while also being used beyond the LHC and even beyond the high-energy physics context. It is, for example, a key tool in data-intensive fields such as astronomy, astroparticle physics and gravitational-wave research. By sharing a common ecosystem for data storage, distribution and analysis, the WLCG enables scientists across disciplines to collaborate efficiently without duplicating resources.

This same flexibility and collaborative approach has also allowed the WLCG to deliver tangible benefits to society: during the COVID-19 pandemic, part of its computing resources was rapidly repurposed to support protein-folding studies. "The WLCG was invented 20 years ago as a technical means to make sure that scientists could do their job. It evolved into something that is more than that - it is a global collaboration that maps onto the collaborative nature of high-energy physics and science in general," summarised Simone Campana, WLCG Project Lead.

The WLCG was a landmark project in the development of distributed computing grids, leveraging efforts from European (EGI) and North American (OSG) e-infrastructures.

Looking ahead, key technologies such as artificial intelligence, and in the longer term quantum computing, have the potential to significantly shape the evolution of the WLCG infrastructure, driving it towards more heterogeneous architectures. "Now we are at the stage where artificial intelligence can really bring us to further improvements and new scientific results," shared Sofia Vallecorsa, coordinator of the CERN Quantum Technology Initiative.

This is particularly important as the scientific community prepares for the data challenges of the High-Luminosity LHC era and beyond.