As blockchain technology evolves rapidly, Layer 3 (L3) is emerging as a new industry focus. L3 acts as an application-specific chain, offering tailored blockchain solutions for particular communities and use cases, such as enterprises, gaming, and social networks. Compared to Layer 2 (L2), L3 goes further in optimizing transaction speed and privacy, making it ideal for more complex applications. This article will introduce the top ten most influential L3 projects, explore their unique features, and assess their potential to drive blockchain innovation forward.