Oracle Hyperion is the EPM wing of Oracle's software offering. Since being acquired in 2007, they have been a big part of Oracle’s BI stack.
Up until their integration with Oracle, they had been a market leader within the performance management space. Their planning, forecasting, and consolidation tools are extremely popular with corporate finance and budgeting departments. The Essbase product was arguably the most popular OLAP engine out in the marketplace. Purchasing them allowed Oracle to have an end-to-end complete solution from reporting to planning to analysis to database. This was seen as the event that kicked off the 2007 BI acquisition spree, with IBM and SAP quickly following suit.
You’ll find most of the old products pushed into the Oracle Business Intelligence Enterprise Edition package today. Hyperion Planning, along with Essbase, is probably the best known of the old products. This is an enterprise-grade planning and forecasting tool, with both web-based and Excel add-in front end capability. Their primary competitors are Cognos Planning and TM1.
Hyperion Financial Management is their financial reporting tool, and used for securities related and accounting and auditing reporting and consolidation. They also have close process functionality. This system is extremely popular in the CFO office for obvious reasons.
Hyperion Strategic Finance is a high level modeling tool for analyzing and doing what-if analysis. Executives can compare different corporate financial strategies and forecast predicted outcomes. Oracle also offers its Crystal Ball software, with predictive analytics as well.
The Essbase engine is the beef behind all of the planning products. The MOLAP power allows for quick work within calculations and consolidation of data up and down an organization. Its also available as a separate product. You can use other front-end reporting tools to access the data within the cubes, but obviously it is more tightly integrated with Oracle technology.
Expertise in these products, combined with the financial and business knowledge, makes filling open jobs tough for recruiting firms.