When you right-click a POM in the UI and select "Download", the POM is downloaded without a content-type header. Depending on the browser, the file can be interpreted as text/plain or text/html, instead of XML.
It's especially annoying in Firefox and Internet Explorer which interpret missing content-type as text/html, so they strip all the tags. This leaves you with a long line of useless concatenated text.
Here's an example for the log4j pom:
root@websphere:~# telnet localhost 8081
Connected to localhost.
Escape character is '^]'.
GET /nexus/content/repositories/central/log4j/log4j/1.2.15/log4j-1.2.15.pom HTTP/1.0
HTTP/1.1 200 OK
Expires: Thu, 01 Jan 1970 00:00:00 GMT
Last-Modified: Thu, 30 Aug 2007 17:41:16 GMT
Date: Tue, 04 Aug 2009 13:44:32 GMT
Vary: Accept-Charset, Accept-Encoding, Accept-Language, Accept
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
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.
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
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