Theatrical enterprises vary enormously in sophistication and purpose. People who are involved vary from novices and hobbyists (in community theatre) to professionals (in Broadway and similar productions). Theatre can be performed with a shoestring budget or on a grand scale with multimillion-dollar budgets. This diversity manifests in the abundance of theatre sub-categories, which include:  While most modern theatre companies rehearse one piece of theatre at a time, perform that piece for a set "run", retire the piece, and begin rehearsing a new show, repertory companies rehearse multiple shows at one time. These companies are able to perform these various pieces upon request and often perform works for years before retiring them. Most dance companies operate on this repertory system. The Royal National Theatre in London performs on a repertory system. Repertory theatre generally involves a group of similarly accomplished actors, and relies more on the reputation of the group than on an individual star actor. It also typically relies less on strict control by a director and less on adherence to theatrical conventions, since actors who have worked together in multiple productions can respond to each other without relying as much on convention or external direction. In order to put on a piece of theatre, both a theatre company and a theatre venue are needed. When a theatre company is the sole company in residence at a theatre venue, this theatre (and its corresponding theatre company) are called a resident theatre or a producing theatre, because the venue produces its own work. Other theatre companies, as well as dance companies, who do not have their own theatre venue, perform at rental theatres or at presenting theatres. Both rental and presenting theatres have no full-time resident companies. They do, however, sometimes have one or more part-time resident companies, in addition to other independent partner companies who arrange to use the space when available. A rental theatre allows the independent companies to seek out the space, while a presenting theatre seeks out the independent companies to support their work by presenting them on their stage. Some performance groups perform in non-theatrical spaces. Such performances can take place outside or inside, in a non-traditional performance space, and include street theatre, and site-specific theatre. Non-traditional venues can be used to create more immersive or meaningful environments for audiences. They can sometimes be modified more heavily than traditional theatre venues, or can accommodate different kinds of equipment, lighting and sets. A touring company is an independent theatre or dance company that travels, often internationally, being presented at a different theatre in each city.