[ALUG] Sharepoint alternatives

A customer has asked us to look at setting up a hosted sharepoint server for them. What are the best FOSS alternatives I should look at to give them some options? -- Mark Rogers // More Solutions Ltd (Peterborough Office) // 0844 251 1450 Registered in England (0456 0902) @ 13 Clarke Rd, Milton Keynes, MK1 1LG