https://markzware.com/products/idmarkz/ Is the only non-script means of .indd conversion without needing ID installed. Currently Mac only but a Windows version is being developed. As far as I know, the only layout application available that can directly open .indd files without ID is Viva Designer version 10. VD has long had the ability to open/save .idml files (in most respects, the best conversion). The .indd format being opened is new to VD version 10 and isn't yet as robust/capable