Buses are the main form of public transport in Nepal. Minibuses, microbuses, tempos (three wheelers) and taxis (cars) are also there.
Local Buses run pretty much everywhere and will stop for anyone. They are incredibly cheap.
Tourist Buses connect popular places and are more comfortable and less crowded.
Metered Taxis are plentiful in Kathmandu, at night the meter reading plus 50% is standard, however you are still have to agree the fare before departure.
Most known taxi companies are:
Taximandu
Pathao Taxi Service