It seems to me that the license displayed in the Eclipse update site installer is typically shorter than the full Apache license, and includes a link to the full license. I don't recall the pros/cons here.
For instance, the "short" version used in the uimaj plugins is: Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0. 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. The version used in textmarker is the full text, including the appendix on how to apply the Apache license to other works. I think, in any case, that Appendix should be omitted here. This is not a blocker, in my opinion, however. -Marshall
