diff --git a/tzk/builders.py b/tzk/builders.py
index 5e67c76..000d682 100644
--- a/tzk/builders.py
+++ b/tzk/builders.py
@@ -13,7 +13,6 @@ information about the defined products without actually running any build steps.
 from collections.abc import Mapping
 from contextlib import contextmanager
 import functools
-import json
 import os
 from pathlib import Path
 import re
@@ -24,7 +23,7 @@ from typing import Callable, Dict, List, Optional, Set, Sequence, Tuple
 
 from tzk import git
 from tzk import tw
-from tzk.util import BuildError, pushd
+from tzk.util import alter_tiddlywiki_info, BuildError, pushd
 
 
 def tzk_builder(func):
@@ -648,8 +647,22 @@ def editionify(target_folder: str, description: str) -> None:
         build_state['public_wiki_folder'],
         target_folder,
     )
-    with (Path(target_folder) / "tiddlywiki.info").open("r") as f:
-        tinfo = json.load(f)
-    tinfo['description'] = description
-    with (Path(target_folder) / "tiddlywiki.info").open("w") as f:
-        json.dump(tinfo, f)
+
+    def editor(tinfo):
+        tinfo['description'] = description
+        return tinfo
+    alter_tiddlywiki_info(Path(target_folder) / "tiddlywiki.info", editor)
+
+
+@tzk_builder
+def add_plugins(plugins: Sequence[str]) -> None:
+    """
+    Add one or more plugins to the tiddlywiki.info file.
+
+    :param plugins: A list of plugin names (e.g., "tiddlywiki/codemirror") to add.
+    """
+    def editor(tinfo):
+        tinfo['plugins'].extend(plugins)
+        return tinfo
+    alter_tiddlywiki_info(Path(build_state['public_wiki_folder']) / "tiddlywiki.info",
+                          editor)
diff --git a/tzk/tw.py b/tzk/tw.py
index c7de2f7..9d3b840 100644
--- a/tzk/tw.py
+++ b/tzk/tw.py
@@ -114,18 +114,28 @@ def _init_tw(wiki_name: str) -> None:
                 os.environ['TIDDLYWIKI_EDITION_PATH'] = old_edition_path
 
 
-def _add_filesystem_plugins(wiki_name: str) -> None:
+def _restore_plugins(wiki_name: str) -> None:
     """
-    Add the "tiddlywiki/filesystem" and "tiddlywiki/tiddlyweb" plugins
-    required for Node.js client-server operation to the new wiki's tiddlywiki.info.
+    Add the plugins from the edition's tiddlywiki.info to the new wiki's
+    tiddlywiki.info (for some reason, this is not done automatically). Also
+    add the two plugins required for client-server operation.
     """
-    print("tzk: Adding filesystem plugins to tiddlywiki.info...")
+    print("tzk: Adding plugins to tiddlywiki.info...")
+
     info_path = Path.cwd() / wiki_name / "tiddlywiki.info"
+    edition_path = Path(__file__).parent / "editions" / "tzk" / "tiddlywiki.info"
+
     with info_path.open("r") as f:
         info_data = json.load(f)
-    info_data['plugins'] = ["tiddlywiki/filesystem", "tiddlywiki/tiddlyweb"]
+    with edition_path.open("r") as f:
+        edition_data = json.load(f)
+    
+    plugins = {"tiddlywiki/filesystem", "tiddlywiki/tiddlyweb"}
+    plugins = plugins.union(edition_data['plugins'])
+    info_data['plugins'] = sorted(plugins)
+
     with info_path.open("w") as f:
-        json.dump(info_data, f)
+        json.dump(info_data, f, indent=4)
 
 
 def _init_gitignore() -> None:
@@ -180,7 +190,7 @@ def install(wiki_name: str, tw_version_spec: str, author: Optional[str],
     else:
         _init_tw(wiki_name)
 
-    _add_filesystem_plugins(wiki_name)
+    _restore_plugins(wiki_name)
     _init_gitignore()
     _initial_commit()
 
diff --git a/tzk/util.py b/tzk/util.py
index 4e76f31..62dd65f 100644
--- a/tzk/util.py
+++ b/tzk/util.py
@@ -2,16 +2,29 @@
 util.py - miscellaneous utility functions
 """
 from contextlib import contextmanager
+import json
 import os
+from pathlib import Path
 import shutil
 import sys
-from typing import NoReturn
+from typing import Any, Callable, Dict, NoReturn
 
 
 class BuildError(Exception):
     pass
 
 
+def alter_tiddlywiki_info(
+        info_path: Path,
+        edit_func: Callable[[Dict[str, Any]], Dict[str, Any]]) -> None:
+    "Change a tiddlywiki.info (or other json file) in an arbitrary manner."
+    with info_path.open("r") as f:
+        tinfo = json.load(f)
+    tinfo = edit_func(tinfo)
+    with info_path.open("w") as f:
+        json.dump(tinfo, f, indent=2)
+
+
 def fail(msg: str, exit_code: int = 1) -> NoReturn:
     "Print message to stderr and quit with exit code 1."
     print(msg, file=sys.stderr)
@@ -54,4 +67,4 @@ def require_dependencies() -> None:
     if shutil.which("git") is None:
         fail("Git is not available. "
                 "Please install Git and make it available on your PATH.\n"
-                "https://git-scm.com/book/en/v2/Getting-Started-Installing-Git")
\ No newline at end of file
+                "https://git-scm.com/book/en/v2/Getting-Started-Installing-Git")