Jainism is a religion founded a few decades before the Buddha’s enlightenment by the sage called Mahavira ‘Great Hero’ by the Jains themselves and Nigaõñha Nàtaputta by the Buddhists (D.I,57). Although Mahàvãra and the Buddha often talked to or debated with each other’s disciples, they never met directly.
Jainism and Buddhism have much in common and it is clear that the Buddha was influenced to some degree by this gentle ascetic faith. However, Mahàvãra taught that any act, intentional or not, creates kamma, whereas the Buddha taught that only intentional actions have a kammic effect. From this difference between the two religions many others follow. The Buddha was critical of both Jain doctrines and of the self-mortification practised by Jain ascetics. For several centuries the two religions vied with each other for supremacy but eventually Buddhism won and Jainism ever after remained a minor religion. Today there are about six million Jains in India, mainly in the western state of Gujarat. There are also now small but vibrant communities of Jains in the UK.
The Jains, Paul Dundas, 2002