Objective-Pascal is a Pascal variant that has been designed by the Mac Pascal community. It has been implemented in the Free Pascal Compiler.
It largely follows the design philosophy of Objective-C++: both regular Object Pascal and Objective-Pascal can be used side by side in the same source file, both have their own inheritance trees and and generally are completely orthogonal to each other.
The state of the language can be found at http://wiki.freepascal.org/FPC_PasCocoa, and an overview with some differences between on the one hand Objective-C and Objective-Pascal, and on the other hand between Object Pascal and Objective-Pascal, is available at http://wiki.freepascal.org/FPC_PasCocoa/Differences. Overall, most common Objective-C 1.0 language features are currently available, and code generation is supported for all Mac OS X platforms (PowerPC 32/64, Intel 32/64, ARM).