diff --git a/repos/spack_repo/builtin/packages/realm/package.py b/repos/spack_repo/builtin/packages/realm/package.py
new file mode 100644
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+++ b/repos/spack_repo/builtin/packages/realm/package.py
@@ -0,0 +1,220 @@
+# Copyright Spack Project Developers. See COPYRIGHT file for details.
+#
+# SPDX-License-Identifier: (Apache-2.0 OR MIT)
+
+from spack_repo.builtin.build_systems.cmake import CMakePackage
+from spack_repo.builtin.build_systems.cuda import CudaPackage
+from spack_repo.builtin.build_systems.rocm import ROCmPackage
+
+from spack.package import *
+
+
+class Realm(CMakePackage, CudaPackage, ROCmPackage):
+    """Realm is a distributed, event–based tasking runtime for building
+    high-performance applications that span clusters of CPUs, GPUs, and other
+    accelerators. It began life as the low-level substrate underneath the Legion
+    programming system but is now maintained as a standalone project for developers
+    who want direct, fine-grained control of parallel and heterogeneous
+    machines."""
+
+    homepage = "https://legion.stanford.edu/realm/"
+    git = "https://github.com/StanfordLegion/realm.git"
+
+    license("Apache-2.0")
+
+    maintainers("elliottslaughter", "rbberger")
+
+    version("main", branch="main")
+
+    depends_on("c", type="build")
+    depends_on("cxx", type="build")
+
+    depends_on("cmake@3.22:", type="build")
+
+    # TODO: Need to spec version of MPI v3 for use of the low-level MPI transport
+    # layer. At present the MPI layer is still experimental and we discourge its
+    # use for general (not legion development) use cases.
+    depends_on("mpi", when="network=mpi")
+    depends_on("ucx", when="network=ucx")
+    depends_on("ucc", when="network=ucx")
+    depends_on("ucc+cuda+nccl", when="network=ucx +cuda")
+    depends_on("ucc+rocm+rccl", when="network=ucx +rocm")
+    depends_on("hdf5", when="+hdf5")
+    depends_on("hwloc", when="+hwloc")
+
+    # Propagate CUDA architectures
+    for arch in CudaPackage.cuda_arch_values:
+        depends_on(f"ucc cuda_arch={arch}", when=f"network=ucx +cuda cuda_arch={arch}")
+        depends_on(f"gasnet +cuda cuda_arch={arch}", when=f"network=gasnet +cuda cuda_arch={arch}")
+        depends_on(
+            f"kokkos+cuda+cuda_lambda cuda_arch={arch}", when=f"+kokkos+cuda cuda_arch={arch}"
+        )
+
+    for arch in ROCmPackage.amdgpu_targets:
+        depends_on(f"ucc amdgpu_target={arch}", when=f"network=ucx +rocm amdgpu_target={arch}")
+        depends_on(
+            f"gasnet +rocm amdgpu_target={arch}", when=f"network=gasnet +rocm amdgpu_target={arch}"
+        )
+        depends_on(f"kokkos+rocm amdgpu_target={arch}", when=f"+kokkos+rocm amdgpu_target={arch}")
+
+    depends_on("kokkos@4:", when="+kokkos")
+    depends_on("kokkos+openmp", when="+kokkos+openmp")
+    depends_on("kokkos~openmp", when="+kokkos~openmp")
+
+    # force same compiler as kokkos if static build
+    depends_on("kokkos %gcc", when="+kokkos~shared %gcc")
+    depends_on("kokkos %clang", when="+kokkos~shared %clang")
+
+    depends_on("python@3.8:", when="+python")
+
+    depends_on("papi", when="+papi")
+
+    # A C++ standard variant to work-around some odd behaviors with apple-clang
+    # but this might be helpful for other use cases down the road. Realm's
+    # current development policy is C++17 or greater so we capture that aspect
+    # here.
+    cpp_stds = ("17", "20")
+    variant("cxxstd", default="17", description="C++ standard", values=cpp_stds, multi=False)
+
+    # Network transport layer: the underlying data transport API should be used for
+    # distributed data movement.  For Realm, GASNet and UCX are the most
+    # mature.  We have many users that default to using no network layer for
+    # day-to-day development thus we default to 'none'.  MPI support is new and
+    # should be considered as a beta release.
+    variant(
+        "network",
+        default="none",
+        values=("gasnet", "mpi", "ucx", "none"),
+        description="The network communications/transport layer to use.",
+        multi=False,
+    )
+
+    with when("network=gasnet"):
+        variant(
+            "conduit",
+            default="smp",
+            values=("smp", "aries", "ibv", "udp", "mpi", "ucx", "ofi-slingshot11"),
+            description="The GASNet conduit(s) to enable.",
+            sticky=True,
+            multi=False,
+        )
+
+    with when("network=ucx"):
+        variant(
+            "ucx_backends",
+            default="p2p",
+            values=("p2p", "mpi"),
+            description="UCX Bootstraps to build and install",
+            multi=True,
+        )
+        requires("ucx_backends=p2p", msg="p2p backend is always enabled")
+
+    variant("shared", default=False, description="Build shared libraries.")
+
+    variant(
+        "log_level",
+        default="warning",
+        # Note: these values are dependent upon those used in the cmake config.
+        values=("spew", "debug", "info", "print", "warning", "error", "fatal", "none"),
+        description="Set the compile-time logging level.",
+        multi=False,
+    )
+
+    with when("+cuda"):
+        variant(
+            "cuda_dynamic_load",
+            default=False,
+            description="Enable dynamic loading of CUDA libraries.",
+        )
+        variant(
+            "cuda_unsupported_compiler",
+            default=False,
+            description="Disable nvcc version check (--allow-unsupported-compiler).",
+        )
+
+    variant("hdf5", default=False, description="Enable support for HDF5.")
+    variant("hwloc", default=False, description="Use hwloc for topology awareness.")
+    variant(
+        "kokkos", default=False, description="Enable support for interoperability with Kokkos."
+    )
+    variant(
+        "libdl", default=True, description="Enable support for dynamic object/library loading."
+    )
+    variant("openmp", default=False, description="Enable support for OpenMP.")
+    variant("papi", default=False, description="Enable PAPI performance measurements.")
+    variant("python", default=False, description="Enable Python support.")
+    requires("+shared", when="+python")
+
+    variant(
+        "max_dims",
+        values=int,
+        default="3",
+        description="Set max number of dimensions for logical regions.",
+    )
+
+    variant(
+        "sysomp", default=False, description="Use system OpenMP implementation instead of Realm's"
+    )
+
+    def cmake_args(self):
+        spec = self.spec
+        from_variant = self.define_from_variant
+        options = [
+            self.define("REALM_ENABLE_INSTALL", True),
+            self.define("REALM_INSTALL", True),  # remove once inconsistency is fixed
+            from_variant("REALM_CXX_STANDARD", "cxxstd"),
+            from_variant("BUILD_SHARED_LIBS", "shared"),
+            self.define("REALM_ENABLE_UCX", spec.satisfies("network=ucx")),
+            self.define("REALM_INSTALL_UCX_BOOTSTRAPS", spec.satisfies("network=ucx")),
+            self.define(
+                "UCX_BOOTSTRAP_ENABLE_MPI", spec.satisfies("network=ucx ucx_backends=mpi")
+            ),
+            self.define("REALM_ENABLE_GASNETEX", spec.satisfies("network=gasnet")),
+            self.define("REALM_ENABLE_MPI", spec.satisfies("network=mpi")),
+            from_variant("REALM_ENABLE_CUDA", "cuda"),
+            from_variant("REALM_ENABLE_HIP", "rocm"),
+            from_variant("REALM_ENABLE_HDF5", "hdf5"),
+            from_variant("REALM_ENABLE_HWLOC", "hwloc"),
+            from_variant("REALM_ENABLE_KOKKOS", "kokkos"),
+            from_variant("REALM_ENABLE_LIBDL", "libdl"),
+            from_variant("REALM_ENABLE_OPENMP", "openmp"),
+            from_variant("REALM_ENABLE_PAPI", "papi"),
+            from_variant("REALM_ENABLE_PYTHON", "python"),
+            from_variant("REALM_CUDA_DYNAMIC_LOAD", "cuda_dynamic_load"),
+            self.define("REALM_OPENMP_SYSTEM_RUNTIME", spec.satisfies("+openmp +sysomp")),
+        ]
+
+        options.append(f"-DREALM_LOG_LEVEL={str.upper(spec.variants['log_level'].value)}")
+
+        # for shared libraries, realm_kokkos.so will be self contained.
+        # however, in the static case we need to use the same compiler/wrapper as kokkos globally.
+        if self.spec.satisfies("~shared+kokkos ^kokkos+wrapper"):
+            options.append(self.define("CMAKE_CXX_COMPILER", self["kokkos"].kokkos_cxx))
+        elif self.spec.satisfies("~shared+kokkos ^kokkos~cmake_lang+rocm"):
+            options.append(self.define("CMAKE_CXX_COMPILER", self.spec["hip"].hipcc))
+
+        if spec.satisfies("+cuda"):
+            options.append(
+                self.define("CMAKE_CUDA_COMPILER", join_path(spec["cuda"].prefix.bin, "nvcc"))
+            )
+            if spec.satisfies("+cuda_unsupported_compiler"):
+                options.append("-DCMAKE_CUDA_FLAGS:STRING=--allow-unsupported-compiler")
+
+            options.append(
+                self.define("CMAKE_CUDA_ARCHITECTURES", spec.variants["cuda_arch"].value)
+            )
+        if spec.satisfies("+rocm"):
+            options.append(
+                self.define(
+                    "CMAKE_HIP_COMPILER", join_path(spec["llvm-amdgpu"].prefix.bin, "amdclang++")
+                )
+            )
+            options.append(
+                self.define("CMAKE_HIP_ARCHITECTURES", spec.variants["amdgpu_target"].value)
+            )
+
+        maxdims = int(spec.variants["max_dims"].value)
+        # TODO: sanity check if maxdims < 0 || > 9???
+        options.append(f"-DREALM_MAX_DIM={maxdims}")
+
+        return options