Inside the Sun: Unsolved Problems.- 1: Solar Modelling.- The Standard Solar Model.- Equation of State and Ionization of Dense Plasmas.- Nuclear Reactions in the Sun.- Solar Opacities Constrained by Solar Neutrinos and Solar Oscillations.- Astrophysical Opacities at LLNL.- Constraints on Solar Models from Stellar Evolution.- Convection in the Sun.- Comments on Solar Convection.- On the Accuracy of Solar Modelling.- A Look on Non-standard Solar Models.- Solar Cosmions.- L'isotope 3He dans les étoiles. Application à la théorie des Novæ et des naines blanches.- 2: Neutrinos.- Solar Neutrino Projects.- Report on the Homestake Chlorine Solar Neutrino Experiment.- The Kamiokande Solar Neutrino Experiment.- The GALLEX Project.- The Baksan Gallium Solar Neutrino Experiment.- Neutrino Masses, Neutrino Oscillations and Dark Matter.- Matter Effects in Neutrino Propagation.- 3: Helioseismology.- A Review of Observational Helioseismology.- Networks for Helioseismic Observations.- Recent Helioseismological Results from Space.- Future Prospects of Helioseismology from Space.- Helioseismic Investigation of Solar Internal Structure.- Using Helioseismic Data to Probe the Hydrogen Abundance in the Solar Core.- Magnetic Field in the Sun's Interior from Oscillation Data.- Variations of the Low I Solar Acoustic Spectrum Correlated with the Activity Cycle..- Stellar Seismology.- Solar and Stellar Cycles.- 4: Solar Cycle, Dynamo and Transport Processes.- The Solar Dynamo.- The Evolution of the Sun's Angular Momentum.- Angular Momentum Transport and Magnetic Fields in the Solar Interior.- Theory of Transport Processes.- Surface Abundances of Light Elements as Diagnostic of Transport Processes in the Sun and Solar-type stars.- Closing Remarks.- Open Questions.- Souvenirs.- Il était une fois un Roi Soleil.../ From the Sun King to the King Sun.- Il y a 200 ans à Versailles.- Some Visual Souvenirs.- List of Participants.- List of Posters Presented at the Conference.- List of Sponsors.- Index of Keywords.