After PDF to InDesign file conversion using PDF2DTP, you can convert INDD to IDML, via the MarkzTools2 app by Markzware:

You can convert PDFs into IDML (InDesign Markup Language), with the help of Markzware’s PDF2DTP (PDF to InDesign) and MarkzTools2. Once you have the PDF as a layered, fully editable InDesign file via PDF2DTP, you can simply convert the INDD file to IDML via MarkzTools2, to complete PDF to IDML document conversion!

You can also drop the original Adobe InDesign files (which were used to create the PDFs) onto MarkzTools2. That will generate IDML files quickly from the INDD files, without the need to install the InDesign program on the machine currently in use.

Markzware continues to support print, publishing and graphic arts users through product optimization and development of high-quality, useful features. Markzware’s MarkzTools2 is part of a file conversion software bundle that can open InDesign CC–CC 2018 files within CS4 and newer files, as well as convert InDesign to IDML.

Low on money, minutes, and CC membership? With MarkzTools2, you can still create IDML files from INDD files, without Creative Cloud. Markzware shows you how, in this MarkzTools2 video:

After PDF to InDesign Conversion, Convert INDD to IDML: MarkzTools2

Learn how to convert PDF to InDesign to IDML, by using Markzware‘s PDF2DTP for InDesign plugin and Markzware’s MarkzTools2 application for Mac. (Watch the video above, for details.)

You can convert a document to IDML by dragging the document icon to the main window in MarkzTools2 (or you can find and choose a document using the File -> Convert menu). When complete, the IDML file will be added to the File -> Recent menu.

Using InDesign’s server to create an IDML can leave you waiting a long time. As an alternative, you could convert your InDesign file to IDML for access within CC, using MarkzTools2.

The application does not need to have InDesign on the machine to create IDML files from InDesign documents.
Source: http://www.printingnews.com/product/12288539/markzware-markztools2-adobe-indesign-cc-2017-support

Some Great Benefits of the MarkzTools Bundle:
• acts independently of Creative Cloud and does not require additional conversion tools, to convert InDesign.
• can create an IDML from any version InDesign file, including a CS5, CS5.5 or CS6 version.
• is simple to operate.
• safeguards your InDesign file (without Adobe InDesign or Creative Cloud), since it creates a backup file.
• can tell InDesign to open the IDML upon completion of conversion. You’ll get a Save dialog with the original document name as the default.

After PDF to InDesign Conversion via Markzware‘s PDF2DTP InDesign Plugin,
Convert INDD to IDML via Markzware’s MarkzTools2 Application:

MarkzTools Bundle Features
• displays the version of the InDesign file you are viewing
• is a stand-alone app
• can batch convert multiple InDesign files
• allows you to convert INDD files, without running an InDesign program.
• supports text hyperlinks.
• supports several languages.
• lets you send AppleScript commands to MarkzTools2 to change the Preferences.
• allows you to set MarkzTools2 to play a sound upon successful file conversion.
• has the ability to import XML files.
• allows you to save as the IDML filename in InDesign.
• lets you choose, if you prefer, to only extract previews, without creating an IDML.

Many InDesign users have decided to continue to design using InDesign CS6, rather than pay for a Creative Cloud subscription. If you need to create IDML files, but don’t have access to Creative Cloud, you can use MarkzTools2 to convert InDesign files to IDML files.

Once PDF to InDesign Conversion is Complete, Drop the InDesign File on
MarkzTools2, to Convert INDD to IDML:

The MarkzTools Mac Bundle Subscription can convert the following InDesign versions to IDML:
• CC 2018
• CC 2017
• CC 2015
• CC 2014
• CC

The MarkzTools for InDesign macOS bundle, which includes the MarkzTools2 app, supports Adobe InDesign CC 2018 to IDML file conversion. Markzware’s standalone InDesign-to-IDML converter also gives QuarkXPress 2018 Mac users the ability to open IDML files created using MarkzTools2.

With IDML, developers can now:
Dynamically generate or modify documents
Deconstruct and reuse portions of documents
Transform document elements using XSLT
Find and modify data within InDesign documents using XPath or XQuery
Use Adobe Flash® Builder® software and the Adobe AIR® runtime to create custom applications and interfaces in front of IDML workflows
Source: https://helpx.adobe.com/indesign/automation.html

Markzware’s MarkzTools2 can convert InDesign file items, including:
• colors
• text attributes
• images
• layers
• linked text boxes
• page positioning
• runarounds
• blends
• tables

The MarkzTools2 app even supports data conversion of Adobe InDesign CC 2018 files to IDML. With MarkzTools2, you can also open IDML documents in recent versions of InDesign down through CS4 and edit those documents.

Buy Markzware’s Low-Cost MarkzTools 12 Month Bundle Subscription, which provides:
• MarkzTools2
• MarkzTools for InDesign CS6 Mac
• MarkzTools for InDesign CS5.5 Mac
• MarkzTools for InDesign CS5 Mac
• MarkzTools and MarkzTools2 updates

For more information, please visit the MarkzTools2 page. Additional Markzware products are available via the Products page. Please also feel free to subscribe to the Markzware Mailing List and interact with Markzware on Twitter, Facebook, LinkedIn, and Google+.

After PDF to InDesign Conversion, Convert INDD to IDML: MarkzTools2