TL;DR of the article, generated automatically.

Steam's achievement sets are now live for all users, with a revamped achievements page.

• Sets: group achievements, each with its own progress bar and trophy.
• Completion: adding new achievements won't break finished sets or game completion.
• DLC: achievements can be tied to DLC and tracked separately from the base game.
• Retired achievements: devs can archive them, keeping them for players who earned them.