Kleene is free and open-source, released by SAP AG under the Apache License, Version 2. The usual legal disclaimers apply. In particular:
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
See the Apache License Website for full details.