Speaking to clients since the new model was introduced in January, the global technology analyst said the steep increase in Oracle licensing costs at most Java users would mean that by 2026, more than 80 per cent of Java applications will be deployed on third-party Java runtimes, up from 65 per cent in 2023.

Gartner has warned that Oracle is ready to test whether users comply with Java licensing terms as it sees them. Gartner said that one in five Java users can expect an Oracle audit in the next three years.

For those who came in late, Oracle acquired Java with its buyout of Sun Microsystems in 2009 and then later set its new Java SE Universal Subscription up as a "simple, low-cost monthly subscription that includes Java SE Licensing and Support for use on Desktops, Servers or Cloud deployments."

The new model is based on a per-employee consumption measure rather than the per-processor. Oracle has explained the new model and published a new price list.

Gartner Associate Principal analyst Nitish Tyagi said that in a hypothetical organisation with 49,500 employees, all of whom are applicable for the "Named User Plus" (NUP) license as per the legacy subscription model. That organisation runs Oracle JDK on 5,000 processors and would pay $742,500 for NUP licenses and $900,000 for processor licenses under the legacy deal. The new Universal Subscription model would cost it about $3,118,500, a 90 per cent increase in price.

"For large organisations, we expect the increase to be two to five times, depending on the number of employees an organisation has. Please remember, Oracle defines employees as part-time, full-time, temporary, agents, contractors as in whosoever supports internal business operations has to be licensed as per the new Java Universal SE Subscription model," he said.

To make sure companies pay up,  Gartner has also estimated that by 2026, one in five organisations using Java applications will be audited by Oracle, leading to "unbudgeted noncompliance fees." By the same year, more than 30 per cent of organisations using Java applications won't comply with their Oracle contracts.

Pressure from Oracle on license costs will mean more than 80 per cent of Java applications will be deployed on third-party Java runtimes by 2026, up from 65 per cent in 2023, Gartner said.

"Clients are moving towards third-party Java runtimes such as Azul, Amazon Coretto, Eclipse Temurin and IBM Semuru since Oracle announced the heavy pricing model. Other surveys also indicate a decline in Oracle JDK usage and an increase in the use of other Java runtimes," Tyagi said.