diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/ArchiveFormat.java b/gitiles-servlet/src/main/java/com/google/gitiles/ArchiveFormat.java
new file mode 100644
index 0000000..16fdf50
--- /dev/null
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/ArchiveFormat.java
@@ -0,0 +1,91 @@
+// Copyright 2013 Google Inc. All Rights Reserved.
+//
+// Licensed 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.
+
+package com.google.gitiles;
+
+import com.google.common.collect.Maps;
+
+import org.eclipse.jgit.api.ArchiveCommand;
+import org.eclipse.jgit.archive.TarFormat;
+import org.eclipse.jgit.archive.Tbz2Format;
+import org.eclipse.jgit.archive.TgzFormat;
+import org.eclipse.jgit.archive.TxzFormat;
+import org.eclipse.jgit.lib.Config;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Collections;
+import java.util.Map;
+
+enum ArchiveFormat {
+  TGZ("application/x-gzip", new TgzFormat()),
+  TAR("application/x-tar", new TarFormat()),
+  TBZ2("application/x-bzip2", new Tbz2Format()),
+  TXZ("application/x-xz", new TxzFormat());
+  // Zip is not supported because it may be interpreted by a Java plugin as a
+  // valid JAR file, whose code would have access to cookies on the domain.
+
+  static final Logger log = LoggerFactory.getLogger(ArchiveFormat.class);
+
+  private final ArchiveCommand.Format<?> format;
+  private final String mimeType;
+
+  private ArchiveFormat(String mimeType, ArchiveCommand.Format<?> format) {
+    this.format = format;
+    this.mimeType = mimeType;
+    ArchiveCommand.registerFormat(name(), format);
+  }
+
+  String getShortName() {
+    return name().toLowerCase();
+  }
+
+  String getMimeType() {
+    return mimeType;
+  }
+
+  String getDefaultSuffix() {
+    return getSuffixes().iterator().next();
+  }
+
+  Iterable<String> getSuffixes() {
+    return format.suffixes();
+  }
+
+  static ArchiveFormat getDefault(Config cfg) {
+    return byExtension(cfg).values().iterator().next();
+  }
+
+  static Map<String, ArchiveFormat> byExtension(Config cfg) {
+    String[] formats = cfg.getStringList("archive", null, "format");
+    if (formats.length == 0) {
+      formats = new String[values().length];
+      for (int i = 0; i < values().length; i++) {
+        formats[i] = values()[i].name();
+      }
+    }
+    Map<String, ArchiveFormat> exts = Maps.newLinkedHashMap();
+    for (String name : formats) {
+      try {
+        ArchiveFormat format = valueOf(name.toUpperCase());
+        for (String ext : format.getSuffixes()) {
+          exts.put(ext, format);
+        }
+      } catch (IllegalArgumentException e) {
+        log.warn("Invalid archive.format {}", name);
+      }
+    }
+    return Collections.unmodifiableMap(exts);
+  }
+}
diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/ArchiveServlet.java b/gitiles-servlet/src/main/java/com/google/gitiles/ArchiveServlet.java
index b7d49dd..a38c463 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/ArchiveServlet.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/ArchiveServlet.java
@@ -17,22 +17,16 @@
 import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;
 import static javax.servlet.http.HttpServletResponse.SC_OK;
 
-import com.google.common.collect.ImmutableMap;
-
 import org.eclipse.jgit.api.ArchiveCommand;
 import org.eclipse.jgit.api.errors.GitAPIException;
-import org.eclipse.jgit.archive.TarFormat;
-import org.eclipse.jgit.archive.Tbz2Format;
-import org.eclipse.jgit.archive.TgzFormat;
-import org.eclipse.jgit.archive.TxzFormat;
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.http.server.ServletUtils;
+import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevWalk;
 
 import java.io.IOException;
 import java.util.Map;
-import java.util.Set;
 
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
@@ -41,42 +35,11 @@
 public class ArchiveServlet extends BaseServlet {
   private static final long serialVersionUID = 1L;
 
-  private enum Format {
-    TAR("application/x-tar", new TarFormat()),
-    TGZ("application/x-gzip", new TgzFormat()),
-    TBZ2("application/x-bzip2", new Tbz2Format()),
-    TXZ("application/x-xz", new TxzFormat());
-    // Zip is not supported because it may be interpreted by a Java plugin as a
-    // valid JAR file, whose code would have access to cookies on the domain.
+  private final Map<String, ArchiveFormat> byExt;
 
-    private final ArchiveCommand.Format<?> format;
-    private final String mimeType;
-
-    private Format(String mimeType, ArchiveCommand.Format<?> format) {
-      this.format = format;
-      this.mimeType = mimeType;
-      ArchiveCommand.registerFormat(name(), format);
-    }
-  }
-
-  private static final Map<String, Format> FORMATS_BY_EXTENSION;
-
-  static {
-    ImmutableMap.Builder<String, Format> exts = ImmutableMap.builder();
-    for (Format format : Format.values()) {
-      for (String ext : format.format.suffixes()) {
-        exts.put(ext, format);
-      }
-    }
-    FORMATS_BY_EXTENSION = exts.build();
-  }
-
-  static Set<String> validExtensions() {
-    return FORMATS_BY_EXTENSION.keySet();
-  }
-
-  public ArchiveServlet() {
+  public ArchiveServlet(Config cfg) {
     super(null);
+    byExt = ArchiveFormat.byExtension(cfg);
   }
 
   @Override
@@ -99,9 +62,9 @@
       walk.release();
     }
 
-    Format format = FORMATS_BY_EXTENSION.get(view.getExtension());
+    ArchiveFormat format = byExt.get(view.getExtension());
     String filename = getFilename(view, rev, view.getExtension());
-    setDownloadHeaders(req, res, filename, format.mimeType);
+    setDownloadHeaders(req, res, filename, format.getMimeType());
     res.setStatus(SC_OK);
 
     try {
diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/CommitSoyData.java b/gitiles-servlet/src/main/java/com/google/gitiles/CommitSoyData.java
index ff879ba..d84721b 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/CommitSoyData.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/CommitSoyData.java
@@ -62,7 +62,7 @@
   /** Valid sets of keys to include in Soy data for commits. */
   public static enum KeySet {
     DETAIL("author", "committer", "sha", "tree", "treeUrl", "parents", "message", "logUrl",
-        "tgzUrl"),
+        "archiveUrl", "archiveType"),
     DETAIL_DIFF_TREE(DETAIL, "diffTree"),
     SHORTLOG("abbrevSha", "url", "shortMessage", "author", "branches", "tags"),
     DEFAULT(DETAIL);
@@ -88,6 +88,7 @@
   private RevWalk walk;
   private GitilesView view;
   private Map<AnyObjectId, Set<Ref>> refsById;
+  private ArchiveFormat archiveFormat;
 
   public CommitSoyData setLinkifier(Linkifier linkifier) {
     this.linkifier = checkNotNull(linkifier, "linkifier");
@@ -99,6 +100,11 @@
     return this;
   }
 
+  public CommitSoyData setArchiveFormat(ArchiveFormat archiveFormat) {
+    this.archiveFormat = checkNotNull(archiveFormat, "archiveFormat");
+    return this;
+  }
+
   public Map<String, Object> toSoyData(HttpServletRequest req, RevCommit commit, KeySet ks)
       throws IOException {
     checkKeys(ks);
@@ -133,8 +139,12 @@
     if (ks.contains("logUrl")) {
       data.put("logUrl", urlFromView(view, commit, GitilesView.log()));
     }
-    if (ks.contains("tgzUrl")) {
-      data.put("tgzUrl", urlFromView(view, commit, GitilesView.archive().setExtension(".tar.gz")));
+    if (ks.contains("archiveUrl")) {
+      data.put("archiveUrl", urlFromView(view, commit,
+          GitilesView.archive().setExtension(archiveFormat.getDefaultSuffix())));
+    }
+    if (ks.contains("archiveType")) {
+      data.put("archiveType", archiveFormat.getShortName());
     }
     if (ks.contains("tree")) {
       data.put("tree", ObjectId.toString(commit.getTree()));
@@ -175,6 +185,9 @@
 
   private void checkKeys(KeySet ks) {
     checkState(!ks.contains("diffTree") || walk != null, "RevWalk required for diffTree");
+    if (ks.contains("archiveUrl") || ks.contains("archiveType")) {
+      checkState(archiveFormat != null, "archive format required");
+    }
   }
 
   // TODO(dborowitz): Extract this.
diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/DiffServlet.java b/gitiles-servlet/src/main/java/com/google/gitiles/DiffServlet.java
index bd97f6f..c34ef9f 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/DiffServlet.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/DiffServlet.java
@@ -15,6 +15,7 @@
 package com.google.gitiles;
 
 import static com.google.common.base.Preconditions.checkNotNull;
+
 import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;
 
 import com.google.common.base.Charsets;
@@ -23,6 +24,7 @@
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.http.server.ServletUtils;
+import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevCommit;
@@ -46,10 +48,12 @@
   private static final String PLACEHOLDER = "id=\"DIFF_OUTPUT_BLOCK\"";
 
   private final Linkifier linkifier;
+  private final ArchiveFormat archiveFormat;
 
-  public DiffServlet(Renderer renderer, Linkifier linkifier) {
+  public DiffServlet(Config cfg, Renderer renderer, Linkifier linkifier) {
     super(renderer);
     this.linkifier = checkNotNull(linkifier, "linkifier");
+    this.archiveFormat = ArchiveFormat.getDefault(checkNotNull(cfg, "cfg"));
   }
 
   @Override
@@ -81,6 +85,7 @@
       if (showCommit) {
         data.put("commit", new CommitSoyData()
             .setLinkifier(linkifier)
+            .setArchiveFormat(archiveFormat)
             .toSoyData(req, walk.parseCommit(view.getRevision().getId())));
       }
       if (!data.containsKey("repositoryName") && (view.getRepositoryName() != null)) {
diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java b/gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java
index cb2e459..6f4468d 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/GitilesFilter.java
@@ -201,7 +201,7 @@
     }
 
     Filter repositoryFilter = new RepositoryFilter(resolver);
-    Filter viewFilter = new ViewFilter(accessFactory, urls, visibilityCache);
+    Filter viewFilter = new ViewFilter(this.config, accessFactory, urls, visibilityCache);
     Filter dispatchFilter = new DispatchFilter(filters, servlets);
 
     ServletBinder root = serveRegex(ROOT_REGEX).through(viewFilter);
@@ -233,17 +233,17 @@
       case REFS:
         return new RefServlet(renderer, timeCache);
       case REVISION:
-        return new RevisionServlet(renderer, linkifier());
+        return new RevisionServlet(config, renderer, linkifier());
       case PATH:
         return new PathServlet(renderer, urls);
       case DIFF:
-        return new DiffServlet(renderer, linkifier());
+        return new DiffServlet(config, renderer, linkifier());
       case LOG:
         return new LogServlet(renderer, linkifier());
       case DESCRIBE:
         return new DescribeServlet();
       case ARCHIVE:
-        return new ArchiveServlet();
+        return new ArchiveServlet(config);
       default:
         throw new IllegalArgumentException("Invalid view type: " + view);
     }
diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/GitilesView.java b/gitiles-servlet/src/main/java/com/google/gitiles/GitilesView.java
index 25e66b8..38ee7e6 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/GitilesView.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/GitilesView.java
@@ -115,7 +115,7 @@
         default:
           break;
       }
-      if (type == Type.ARCHIVE) {
+      if (type == Type.ARCHIVE && other.type == Type.ARCHIVE) {
         extension = other.extension;
       }
       // Don't copy params.
diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/RevisionServlet.java b/gitiles-servlet/src/main/java/com/google/gitiles/RevisionServlet.java
index bf9de35..c22d627 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/RevisionServlet.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/RevisionServlet.java
@@ -15,7 +15,9 @@
 package com.google.gitiles;
 
 import static com.google.common.base.Preconditions.checkNotNull;
+
 import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;
+
 import static org.eclipse.jgit.lib.Constants.OBJ_BLOB;
 import static org.eclipse.jgit.lib.Constants.OBJ_COMMIT;
 import static org.eclipse.jgit.lib.Constants.OBJ_TAG;
@@ -28,6 +30,7 @@
 import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.http.server.ServletUtils;
+import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.Repository;
@@ -51,10 +54,12 @@
   private static final Logger log = LoggerFactory.getLogger(RevisionServlet.class);
 
   private final Linkifier linkifier;
+  private final ArchiveFormat archiveFormat;
 
-  public RevisionServlet(Renderer renderer, Linkifier linkifier) {
+  public RevisionServlet(Config cfg, Renderer renderer, Linkifier linkifier) {
     super(renderer);
     this.linkifier = checkNotNull(linkifier, "linkifier");
+    this.archiveFormat = ArchiveFormat.getDefault(checkNotNull(cfg, "cfg"));
   }
 
   @Override
@@ -78,6 +83,7 @@
                   "data", new CommitSoyData()
                       .setLinkifier(linkifier)
                       .setRevWalk(walk)
+                      .setArchiveFormat(archiveFormat)
                       .toSoyData(req, (RevCommit) obj, KeySet.DETAIL_DIFF_TREE)));
               break;
             case OBJ_TREE:
diff --git a/gitiles-servlet/src/main/java/com/google/gitiles/ViewFilter.java b/gitiles-servlet/src/main/java/com/google/gitiles/ViewFilter.java
index 5b373de..4f60c12 100644
--- a/gitiles-servlet/src/main/java/com/google/gitiles/ViewFilter.java
+++ b/gitiles-servlet/src/main/java/com/google/gitiles/ViewFilter.java
@@ -19,17 +19,21 @@
 
 import static javax.servlet.http.HttpServletResponse.SC_NOT_FOUND;
 
-import org.eclipse.jgit.http.server.ServletUtils;
-import org.eclipse.jgit.http.server.glue.WrappedRequest;
-
 import java.io.IOException;
 import java.util.Map;
+import java.util.Set;
 
 import javax.servlet.FilterChain;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
+import org.eclipse.jgit.http.server.ServletUtils;
+import org.eclipse.jgit.http.server.glue.WrappedRequest;
+import org.eclipse.jgit.lib.Config;
+
+import com.google.common.collect.Sets;
+
 /** Filter to parse URLs and convert them to {@link GitilesView}s. */
 public class ViewFilter extends AbstractHttpFilter {
   // TODO(dborowitz): Make this public in JGit (or implement getRegexGroup
@@ -76,12 +80,14 @@
   private final GitilesUrls urls;
   private final GitilesAccess.Factory accessFactory;
   private final VisibilityCache visibilityCache;
+  private final Set<String> archiveExts;
 
-  public ViewFilter(GitilesAccess.Factory accessFactory, GitilesUrls urls,
-      VisibilityCache visibilityCache) {
+  public ViewFilter(Config cfg, GitilesAccess.Factory accessFactory,
+      GitilesUrls urls, VisibilityCache visibilityCache) {
     this.urls = checkNotNull(urls, "urls");
     this.accessFactory = checkNotNull(accessFactory, "accessFactory");
     this.visibilityCache = checkNotNull(visibilityCache, "visibilityCache");
+    this.archiveExts = Sets.newHashSet(ArchiveFormat.byExtension(cfg).keySet());
   }
 
   @Override
@@ -142,7 +148,7 @@
   private GitilesView.Builder parseArchiveCommand(
       HttpServletRequest req, String repoName, String path) throws IOException {
     String ext = null;
-    for (String e : ArchiveServlet.validExtensions()) {
+    for (String e : archiveExts) {
       if (path.endsWith(e)) {
         path = path.substring(0, path.length() - e.length());
         ext = e;
diff --git a/gitiles-servlet/src/main/resources/com/google/gitiles/templates/ObjectDetail.soy b/gitiles-servlet/src/main/resources/com/google/gitiles/templates/ObjectDetail.soy
index 2d3a259..73ac298 100644
--- a/gitiles-servlet/src/main/resources/com/google/gitiles/templates/ObjectDetail.soy
+++ b/gitiles-servlet/src/main/resources/com/google/gitiles/templates/ObjectDetail.soy
@@ -36,7 +36,8 @@
  *     url: URL to a detail page for the tree entry.
  *     diffUrl: URL to a diff page for the tree entry's diff in this commit.
  * @param logUrl URL to a log page starting at this commit.
- * @param tgzUrl URL to a download link of this commit as a tarball.
+ * @param archiveUrl URL to a download link of this commit as an archive.
+ * @param archiveType type of the archive to download.
  */
 {template .commitDetail}
 <div class="git-commit">
@@ -48,9 +49,7 @@
         <span class="log-link">
           [<a href="{$logUrl}">{msg desc="text for the log link"}log{/msg}</a>]
         </span>
-        <span class="download-link">
-          [<a href="{$tgzUrl}">{msg desc="text for the tarball link"}tgz{/msg}</a>]
-        </span>
+        <span class="download-link">[<a href="{$archiveUrl}">{$archiveType}</a>]</span>
       </td>
       <td>{sp}</td>
     </tr>
diff --git a/gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java b/gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java
index 0f00174..201ac9d 100644
--- a/gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java
+++ b/gitiles-servlet/src/test/java/com/google/gitiles/ViewFilterTest.java
@@ -36,6 +36,7 @@
 import org.eclipse.jgit.internal.storage.dfs.DfsRepositoryDescription;
 import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository;
 import org.eclipse.jgit.junit.TestRepository;
+import org.eclipse.jgit.lib.Config;
 import org.eclipse.jgit.revwalk.RevCommit;
 
 import com.google.common.collect.ImmutableList;
@@ -421,6 +422,7 @@
     };
 
     ViewFilter vf = new ViewFilter(
+        new Config(),
         new TestGitilesAccess(repo.getRepository()),
         TestGitilesUrls.URLS,
         new VisibilityCache(false));