why Oracle's is owning so many free software under GNU license

While installing MySQL, saw Oracle in the list, was surprised why Oracle is owning all the Free software now days. Does it want to kill the competition by buying all the free s/w and then killing it slowly or its other way of making money by migrating code and features from free code to its DB and strengthen its portfolio. :)

Whatever the case Its the Leading Database company, with lot of free db's in its kitty.

Oracle Database - Wikipedia, the free encyclopedia

Other databases marketed by Oracle Corporation

By acquiring other technology in the database field, Oracle Corporation can also offer:

TimesTen, a memory-resident database that can cache transactions and synchronize data with a centralized Oracle database server. It functions as a real-time infrastructure software product intended for the management of low-latency, high-volume data, of events and of transactions.
BerkeleyDB, a simple, high-performance, embedded database
Oracle Rdb, a legacy relational database for the OpenVMS operating-system
MySQL a relational database purchased as part of Oracle Corporation's takeover of its immediate previous owner, Sun Microsystems