IOC stands for inversion of control. There are serveral implementations for this like:

• Spring
• Seam
• and lot's of others

Spring probably the most used one. Seam is coming up. Spring is chosen because it has a good track record and the team knows it.

For the peristence layer, two types of configuration styles can be used

• jpa style (at this moment not possible to use Hibernate search)
• hibernate style (possible to use Hibernate Search)

For the reasons mentioned the Spring configuration in Hibernate style is chosen.