Since 2004, the Conference on Complex Systems organized by the CSS, is the most important annual meeting for the complex systems research community. Until 2014, it was the European Conference on Complex Systems. In 2015, it became CCS with its first "global" edition in the USA. In 2016, CCS came back to Europe and took place in Amsterdam, Netherlands. In 2017, CCS was organized in Cancun, Mexico, for its first edition in Latin America.
CCS2025 will be in Siena, Italy, from the 1st to the 5th of September. The warm-up will take place also in Siena, Italy, from the 29-30 August 2025.