Moore's law is a historical trend of integrated circuit development: the density of transistors can be doubled every two years. It was posited by Gordon Moore in 1965. Several experts, including Moore himself, have predicted that the trend will end by 2025.
While there are definitely good aspects in Moore's law (including the improvement of energy and material efficiency), it has also come with economical, technological and philosophical side effects.
Perhaps the most prominent of these is an extreme form of Jevons paradox: a dramatic increase in resource efficiency has led to a dramatic increase in resource use. In software, Jevons paradox manifests as Wirth's law: software becomes slower (more bloated, less energy-efficient) more rapidly than hardware becomes faster (more energy-efficient). Jevons paradox is also a major driver of obsolescence.
Moore's law is not a "law of physics" but depends on inreasing economic investments: Moore's second law, also known as Rock's law, states that the cost of a state-of-the-art fabrication plant doubles every four years. The smaller the feature size, the more specialization and complexity is needed in equipment and processes. This has lead to extreme ?centralization of fabs.
Philosophically, Moore's law has given a lot of room to maximalism, including the idea that technological progress is mostly increase of quantity rather than change of quality. The emphasis on quantitative maximization easily leads to maximization of energy and resource use.
Permacomputing welcomes efficiency improvements without the afore-mentioned side effects. It therefore emphasizes lifespan maximization, small-scale and local production, minimization and non-maximalist aesthetics.
Gordon Moore is not to be confused with Chuck Moore, the creator of Forth, nor with Max More, a proponent of extropianism.