Twenty-eight years after the first charters opened in Colorado, they’re more popular than ever, statistics show. They’ve become desirable because there’s something for everyone, said Amanda Oberg, spokeswoman for the Colorado Charter School Institute. With leniency allowed in governance, curriculum and operations, charter schools use educational models such as classical education, Core Knowledge curriculum, project-based learning, language immersion, the Montessori technique, alternative education with adjustable schedules, early college programs, a focus on the arts, technical trades or technology, and other options. Schools have autonomy from school districts, including on scheduling when school is in session, but are still held accountable by districts and the state and must meet benchmarks, said Harris, who's the spokeswoman for The Classical Academy.