Civilization Technology Tree adds a tech tree system to Minecraft. It is a good fit for roleplay and civilization servers where players build up their progress step by step over time.

If you haven't unlocked a tech, you can't use or craft locked items like stone tools. You unlock techs using Science Points, which you get passively just by playing. There is also a discount system: if you complete a specific quest, the tech will cost less points to learn. You can check all your progress and the tech tree in a GUI menu, which opens when you right-click the compass you get when you spawn.