The European Social Survey has published the data of the CROss-National Online Survey (CRONOS) panel, a cross-national web survey pilot panel, run in three countries in Europe: Great Britain, Slovenia, and Estonia.
CRONOS data is available free for download and on-line analysis for non-commercial use. It allows for exploratory substantive analysis and experimental data provide an opportunity for methodological research.
The data and documentation on the CRONOS panel is available here. The release includes data from one welcome survey and 6 waves of data collection; it also contains survey paradata and information on the correspondence with sample members. The CRONOS datasets can also been linked to the ESS Round 8 data.