Software support firm Rimini Street has launched a countersuit against Oracle alleging anti-competitive practices and trade libel.
Oracle originally sued Rimini in January, claiming that the company had stolen large amounts of Oracle's intellectual property.
Rimini has now countersued, insisting that Oracle has spent the past five years trying to destroy the small software house.
"Rimini looks forward to positively resolving its disputes with Oracle, and we remain focused on continuing to deliver award-winning, ultra-responsive services to our fast-growing client base that seeks better software support value," said Seth Ravin, president of Rimini.
"Rimini will also continue to aggressively innovate its service offering and expand to even more software product lines as we continue to execute against our business plan."
The company described Oracle's legal case as "baseless", and said that the technology giant had blocked Rimini's intellectual property and interfered with its work illegally. Rimini has tried to contact Oracle directly, it said, but had been rebuffed.
Oracle is holding firm to its line that it has done nothing wrong and is merely defending its intellectual property.
"Oracle is committed to customer choice and vigorous competition, but draws the line with any company, big or small, that steals its intellectual property, " said the company in a statement.
"The massive theft that Rimini and Mr Ravin engaged in is not healthy competition. We will prove this in court."
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