diff --git a/compiler/docgen.nim b/compiler/docgen.nim
index 75b599ae91..63883af5cb 100644
--- a/compiler/docgen.nim
+++ b/compiler/docgen.nim
@@ -517,12 +517,11 @@ proc genItem(d: PDoc, n, nameNode: PNode, k: TSymKind) =
       path = path[cwd.len+1 .. ^1].replace('\\', '/')
     let gitUrl = getConfigVar(d.conf, "git.url")
     if gitUrl.len > 0:
-      var commit = getConfigVar(d.conf, "git.commit")
-      if commit.len == 0: commit = "master"
+      let commit = getConfigVar(d.conf, "git.commit", "master")
+      let develBranch = getConfigVar(d.conf, "git.devel", "devel")
       dispA(d.conf, seeSrcRope, "$1", "", [ropeFormatNamedVars(d.conf, docItemSeeSrc,
-          ["path", "line", "url", "commit"], [rope path,
-          rope($n.info.line), rope gitUrl,
-          rope commit])])
+          ["path", "line", "url", "commit", "devel"], [rope path,
+          rope($n.info.line), rope gitUrl, rope commit, rope develBranch])])
 
   add(d.section[k], ropeFormatNamedVars(d.conf, getConfigVar(d.conf, "doc.item"),
     ["name", "header", "desc", "itemID", "header_plain", "itemSym",
diff --git a/compiler/options.nim b/compiler/options.nim
index 7cca403212..fcbb98fe63 100644
--- a/compiler/options.nim
+++ b/compiler/options.nim
@@ -406,8 +406,8 @@ proc mainCommandArg*(conf: ConfigRef): string =
 proc existsConfigVar*(conf: ConfigRef; key: string): bool =
   result = hasKey(conf.configVars, key)
 
-proc getConfigVar*(conf: ConfigRef; key: string): string =
-  result = conf.configVars.getOrDefault key
+proc getConfigVar*(conf: ConfigRef; key: string, default = ""): string =
+  result = conf.configVars.getOrDefault(key, default)
 
 proc setConfigVar*(conf: ConfigRef; key, val: string) =
   conf.configVars[key] = val
diff --git a/config/nimdoc.cfg b/config/nimdoc.cfg
index 6b6ec2d833..96e91283a4 100644
--- a/config/nimdoc.cfg
+++ b/config/nimdoc.cfg
@@ -55,6 +55,8 @@ doc.item.toc = """
 # HTML rendered for doc.item's seeSrc variable. Note that this will render to
 # the empty string if you don't pass anything through --docSeeSrcURL. Available
 # substitutaion variables here are:
+# * $commit: branch/commit to use in source link.
+# * $devel: branch to use in edit link.
 # * $path: relative path to the file being processed.
 # * $line: line of the item in the original source file.
 # * $url: whatever you did pass through the --docSeeSrcUrl switch (which also
@@ -62,7 +64,7 @@ doc.item.toc = """
 doc.item.seesrc = """&nbsp;&nbsp;<a
 href="${url}/tree/${commit}/${path}#L${line}"
 class="link-seesrc" target="_blank">Source</a>
-<a href="${url}/edit/devel/${path}#L${line}" class="link-seesrc" target="_blank" >Edit</a>
+<a href="${url}/edit/${devel}/${path}#L${line}" class="link-seesrc" target="_blank" >Edit</a>
 """
 
 doc.toc = """
diff --git a/koch.nim b/koch.nim
index 9411a95de3..133c7e32bd 100644
--- a/koch.nim
+++ b/koch.nim
@@ -50,6 +50,7 @@ Boot options:
 
 Commands for core developers:
   web [options]            generates the website and the full documentation
+                           (see `nimweb.nim` for cmd line options)
   website [options]        generates only the website
   csource -d:release       builds the C sources for installation
   pdf                      builds the PDF documentation
diff --git a/tools/nimweb.nim b/tools/nimweb.nim
index 6e1d9d3596..e74b081eaf 100644
--- a/tools/nimweb.nim
+++ b/tools/nimweb.nim
@@ -13,16 +13,18 @@ import
 
 from xmltree import escape
 
-const gitRepo = "https://github.com/nim-lang/Nim"
-
 type
   TKeyValPair = tuple[key, id, val: string]
   TConfigData = object of RootObj
     tabs, links: seq[TKeyValPair]
     doc, srcdoc, srcdoc2, webdoc, pdf: seq[string]
-    authors, projectName, projectTitle, logo, infile, outdir, ticker: string
+    authors, projectName, projectTitle, logo, infile, ticker: string
     vars: StringTableRef
+    nimCompiler: string
     nimArgs: string
+    gitURL: string
+    docHTMLOutput: string
+    webUploadOutput: string
     quotations: Table[string, tuple[quote, author: string]]
     numProcessors: int # Set by parallelBuild:n, only works for values > 0.
     gaId: string  # google analytics ID, nil means analytics are disabled
@@ -51,8 +53,10 @@ proc initConfigData(c: var TConfigData) =
   c.webdoc = @[]
   c.pdf = @[]
   c.infile = ""
-  c.outdir = ""
   c.nimArgs = "--hint[Conf]:off --hint[Path]:off --hint[Processing]:off -d:boot "
+  c.gitURL = "https://github.com/nim-lang/Nim"
+  c.docHTMLOutput = "doc/html"
+  c.webUploadOutput = "web/upload"
   c.authors = ""
   c.projectTitle = ""
   c.projectName = ""
@@ -79,14 +83,19 @@ const
 Usage:
   nimweb [options] ini-file[.ini] [compile_options]
 Options:
-  -o, --output:dir    set the output directory (default: same as ini-file)
-  --var:name=value    set the value of a variable
   -h, --help          shows this help
   -v, --version       shows the version
+  -o, --output        overrides output directory instead of default
+                      web/upload and doc/html
+  --nimCompiler       overrides nim compiler; default = bin/nim
+  --var:name=value    set the value of a variable
   --website           only build the website, not the full documentation
   --pdf               build the PDF version of the documentation
   --json2             build JSON of the documentation
   --onlyDocs          build only the documentation
+  --git.url           override base url in generated doc links
+  --git.commit        override commit/branch in generated doc links 'source'
+  --git.devel         override devel branch in generated doc links 'edit'
 Compile_options:
   will be passed to the Nim compiler
 """
@@ -145,7 +154,11 @@ proc parseCmdLine(c: var TConfigData) =
       of "version", "v":
         stdout.write(version & "\n")
         quit(0)
-      of "o", "output": c.outdir = val
+      of "output", "o":
+        c.webUploadOutput = val
+        c.docHTMLOutput = val / "docs"
+      of "nimcompiler":
+        c.nimCompiler = val
       of "parallelbuild":
         try:
           let num = parseInt(val)
@@ -163,8 +176,14 @@ proc parseCmdLine(c: var TConfigData) =
       of "googleanalytics":
         c.gaId = val
         c.nimArgs.add("--doc.googleAnalytics:" & val & " ")
+      of "git.url":
+        c.gitURL = val
+      of "git.commit":
+        c.nimArgs.add("--git.commit:" & val & " ")
+      of "git.devel":
+        c.nimArgs.add("--git.devel:" & val & " ")
       else:
-        echo("Invalid argument $1" % [key])
+        echo("Invalid argument '$1'" % [key])
         quit(usage)
     of cmdEnd: break
   if c.infile.len == 0: quit(usage)
@@ -244,15 +263,14 @@ proc parseIniFile(c: var TConfigData) =
   close(p)
   if c.projectName.len == 0:
     c.projectName = changeFileExt(extractFilename(c.infile), "")
-  if c.outdir.len == 0:
-    c.outdir = splitFile(c.infile).dir
 
 # ------------------- main ----------------------------------------------------
 
 
 proc exe(f: string): string = return addFileExt(f, ExeExt)
 
-proc findNim(): string =
+proc findNim(c: TConfigData): string =
+  if c.nimCompiler.len > 0: return c.nimCompiler
   var nim = "nim".exe
   result = "bin" / nim
   if existsFile(result): return
@@ -289,9 +307,9 @@ proc buildDocSamples(c: var TConfigData, destPath: string) =
   ## it didn't make much sense to integrate into the existing generic
   ## documentation builders.
   const src = "doc"/"docgen_sample.nim"
-  exec(findNim() & " doc $# -o:$# $#" %
+  exec(findNim(c) & " doc $# -o:$# $#" %
     [c.nimArgs, destPath / "docgen_sample.html", src])
-  exec(findNim() & " doc2 $# -o:$# $#" %
+  exec(findNim(c) & " doc2 $# -o:$# $#" %
     [c.nimArgs, destPath / "docgen_sample2.html", src])
 
 proc pathPart(d: string): string = splitFile(d).dir.replace('\\', '/')
@@ -302,23 +320,23 @@ proc buildDoc(c: var TConfigData, destPath: string) =
     commands = newSeq[string](len(c.doc) + len(c.srcdoc) + len(c.srcdoc2))
     i = 0
   for d in items(c.doc):
-    commands[i] = findNim() & " rst2html $# --git.url:$# -o:$# --index:on $#" %
-      [c.nimArgs, gitRepo,
+    commands[i] = findNim(c) & " rst2html $# --git.url:$# -o:$# --index:on $#" %
+      [c.nimArgs, c.gitURL,
       destPath / changeFileExt(splitFile(d).name, "html"), d]
     i.inc
   for d in items(c.srcdoc):
-    commands[i] = findNim() & " doc0 $# --git.url:$# -o:$# --index:on $#" %
-      [c.nimArgs, gitRepo,
+    commands[i] = findNim(c) & " doc0 $# --git.url:$# -o:$# --index:on $#" %
+      [c.nimArgs, c.gitURL,
       destPath / changeFileExt(splitFile(d).name, "html"), d]
     i.inc
   for d in items(c.srcdoc2):
-    commands[i] = findNim() & " doc2 $# --git.url:$# -o:$# --index:on $#" %
-      [c.nimArgs, gitRepo,
+    commands[i] = findNim(c) & " doc2 $# --git.url:$# -o:$# --index:on $#" %
+      [c.nimArgs, c.gitURL,
       destPath / changeFileExt(splitFile(d).name, "html"), d]
     i.inc
 
   mexec(commands, c.numProcessors)
-  exec(findNim() & " buildIndex -o:$1/theindex.html $1" % [destPath])
+  exec(findNim(c) & " buildIndex -o:$1/theindex.html $1" % [destPath])
 
 proc buildPdfDoc(c: var TConfigData, destPath: string) =
   createDir(destPath)
@@ -327,7 +345,7 @@ proc buildPdfDoc(c: var TConfigData, destPath: string) =
   else:
     const pdflatexcmd = "pdflatex -interaction=nonstopmode "
     for d in items(c.pdf):
-      exec(findNim() & " rst2tex $# $#" % [c.nimArgs, d])
+      exec(findNim(c) & " rst2tex $# $#" % [c.nimArgs, d])
       # call LaTeX twice to get cross references right:
       exec(pdflatexcmd & changeFileExt(d, "tex"))
       exec(pdflatexcmd & changeFileExt(d, "tex"))
@@ -347,8 +365,8 @@ proc buildAddDoc(c: var TConfigData, destPath: string) =
   # build additional documentation (without the index):
   var commands = newSeq[string](c.webdoc.len)
   for i, doc in pairs(c.webdoc):
-    commands[i] = findNim() & " doc2 $# --git.url:$# -o:$# $#" %
-      [c.nimArgs, gitRepo,
+    commands[i] = findNim(c) & " doc2 $# --git.url:$# -o:$# $#" %
+      [c.nimArgs, c.gitURL,
       destPath / changeFileExt(splitFile(doc).name, "html"), doc]
   mexec(commands, c.numProcessors)
 
@@ -431,9 +449,9 @@ proc buildNewsRss(c: var TConfigData, destPath: string) =
 
   generateRss(destFilename, parseNewsTitles(srcFilename))
 
-proc buildJS(destPath: string) =
-  exec(findNim() & " js -d:release --out:$1 web/nimblepkglist.nim" %
-      [destPath / "nimblepkglist.js"])
+proc buildJS(c: TConfigData) =
+  exec(findNim(c) & " js -d:release --out:$1 web/nimblepkglist.nim" %
+      [c.webUploadOutput / "nimblepkglist.js"])
 
 proc readSponsors(sponsorsFile: string): seq[Sponsor] =
   result = @[]
@@ -464,7 +482,7 @@ const
   cmdRst2Html = " rst2html --compileonly $1 -o:web/$2.temp web/$2.rst"
 
 proc buildPage(c: var TConfigData, file, title, rss: string, assetDir = "") =
-  exec(findNim() & cmdRst2Html % [c.nimArgs, file])
+  exec(findNim(c) & cmdRst2Html % [c.nimArgs, file])
   var temp = "web" / changeFileExt(file, "temp")
   var content: string
   try:
@@ -472,7 +490,7 @@ proc buildPage(c: var TConfigData, file, title, rss: string, assetDir = "") =
   except IOError:
     quit("[Error] cannot open: " & temp)
   var f: File
-  var outfile = "web/upload/$#.html" % file
+  var outfile = c.webUploadOutput / "$#.html" % file
   if not existsDir(outfile.splitFile.dir):
     createDir(outfile.splitFile.dir)
   if open(f, outfile, fmWrite):
@@ -502,27 +520,25 @@ proc buildWebsite(c: var TConfigData) =
     let rss = if file in ["news", "index"]: extractFilename(rssUrl) else: ""
     if '.' in file: continue
     buildPage(c, file, if file == "question": "FAQ" else: file, rss)
-  copyDir("web/assets", "web/upload/assets")
-  buildNewsRss(c, "web/upload")
-  buildSponsors(c, "web/upload")
-  buildNews(c, "web/news", "web/upload/news")
+  copyDir("web/assets", c.webUploadOutput / "assets")
+  buildNewsRss(c, c.webUploadOutput)
+  buildSponsors(c, c.webUploadOutput)
+  buildNews(c, "web/news", c.webUploadOutput / "news")
+
+proc onlyDocs(c: var TConfigData) =
+  createDir(c.docHTMLOutput)
+  buildDocSamples(c, c.docHTMLOutput)
+  buildDoc(c, c.docHTMLOutput)
 
 proc main(c: var TConfigData) =
   buildWebsite(c)
-  buildJS("web/upload")
-  const docup = "web/upload/" & NimVersion
+  buildJS(c)
+  let docup = c.webUploadOutput / NimVersion
   createDir(docup)
   buildAddDoc(c, docup)
   buildDocSamples(c, docup)
   buildDoc(c, docup)
-  createDir("doc/html")
-  buildDocSamples(c, "doc/html")
-  buildDoc(c, "doc/html")
-
-proc onlyDocs(c: var TConfigData) =
-  createDir("doc/html")
-  buildDocSamples(c, "doc/html")
-  buildDoc(c, "doc/html")
+  onlyDocs(c)
 
 proc json2(c: var TConfigData) =
   const destPath = "web/json2"
@@ -530,8 +546,8 @@ proc json2(c: var TConfigData) =
   var i = 0
   for d in items(c.srcdoc2):
     createDir(destPath / splitFile(d).dir)
-    commands[i] = findNim() & " jsondoc2 $# --git.url:$# -o:$# --index:on $#" %
-      [c.nimArgs, gitRepo,
+    commands[i] = findNim(c) & " jsondoc2 $# --git.url:$# -o:$# --index:on $#" %
+      [c.nimArgs, c.gitURL,
       destPath / changeFileExt(d, "json"), d]
     i.inc