You say:

Groovy is not 100% identical

Then you say:

JPlus aims to keep Java syntax almost intact

Which implies that it is not 100% identical either.

So why do you apply that same argument against one but not the other? Seems like marketing bs.

As you mentioned, the phrasing might make it seem inconsistent. The key difference here is not whether they are “100% identical,” but the degree and nature of the changes.

Groovy introduces dynamic typing, optional syntax, runtime behaviors, and other language features that can fundamentally alter how Java code executes. Even if the code compiles, subtle differences in behavior can occur. In contrast, JPlus preserves nearly all standard Java syntax while only adding compile-time null-safety checks and boilerplate code generation. These changes have minimal impact on the execution of existing Java code and are primarily intended to improve safety and developer convenience.

Additionally, JPlus is currently developed based on Java 20 syntax, with added null-safety and boilerplate code generation features. Therefore, code up to Java 20 is fully compatible. Since future updates will support the latest Java syntax as well, the phrasing “almost identical” is used intentionally. In practice, JPlus will continue to be Java syntax + α.

Technically, neither language is “100% identical” to Java, but the practical impact is very different. Groovy can alter runtime behavior, whereas JPlus preserves existing behavior almost entirely while adding safety and developer convenience. This is not marketing exaggeration, but a reflection of the difference in the invasiveness of changes.