Eve Online, from developer CCP Games, has often been noted as one of the most intense learning curves in gaming. With the newest expansion, Ascension, Eve Online has ascended into the realm of free-to-play for the first time in its 13 year history.
The expansion added clone states, with there being Alpha and Omega clones, being free-to-play and the subscription based, receptively. Alpha clones get free access to game and have a limited skill system that are race specific to the character. This does include high tier skills for tech one ships and basic access into industry and trading. These skills will, however, take longer to train than those on Omega clones, and will not allow access to many higher level ships.
Also included in the expansion is Inception, the first phase of the new story line campaign to teach new players the foundations of being a capsuleer. This is the first chapter of a larger system coming later, as described in the dev blog.
Omega clones see no change and will continue to pay their monthly subscription and have access to all game aspects. This blog post goes into much deeper detail explaining the intricacies of the change.