Open Source Software can be great. TechCruch lists 5 fairly new open source technologies for big data.
This is probably a good list to pay attention to for the near future.

• Storm
• Drill
• R
• Gremlin
• SAP Hana

If you are unfamiliar with some of software on the list, please read the article for more details.

Big Data Right Now: Five Trendy Open Source Technologies | TechCrunch.