OpenDataForge is a collection of proprietary tools for transforming data. At the time of writing, three tools are available:

  • SledgeHammer can be used for migrating data from formats like Stata, SPSS and SAS into fixed-length field or delimited text files, including CSV. It can also generate DDI Codebook and LifeCycle metadata, Triple-S interchange files, summary statistics, and scripts for importing the ASCII data files into various statistical packages and databases.
  • Caelum generates HTML and PDF reports from XML files using XSLT.
  • Asmurex takes a multi-record fixed-length field text file and from it generates a separate file for each record type.


The tools are developed by MTNA (Metadata Technology North America), a commercial company that provides consulting, training and technology supporting the SDMX and DDI standards.

Licensing and cost

The Community Edition of SledgeHammer is free, but is limited to 100 variables and 1000 records per dataset. The Registered Edition is free in exchange for registration information, and is limited to 500 variables and 5000 records per dataset. The Professional Edition has extra features and no limits on the variables or records per dataset; a subscription costs $29 for 3 months or $99 for one year at the time of writing, while a perpetual licence costs $279.

Caelum and Asmurex are both free to download and use under the terms of the OpenDataForge Community Edition License Agreement. This agreement also applies to use of the Community Edition of SledgeHammer.

Development activity

Sledgehammer: version 1.0.20140801 was released in August 2014.

Caelum: version 2013.22.31 was released in May 2013.

Asmurex: version 1.0.0 was released in September 2013.

Platform and interoperability

The tools are written in Java 1.6 and are therefore platform independent, though compiled binary versions of SledgeHammer are available for Windows and Mac OSX.

Caelum appears to require the Saxon HE XSLT library version 9.0 or 9.1 for Java.

Functional notes

SledgeHammer can read data and extract metadata from Stata, SPSS, SAS, DDI+ASCII and Stat/Transfer+ASCII. It can output files as DDI Codebook versions 1.0-2.1 and 2.5, DDI LifeCycle versions 3.1-3.2, and Triple-S version 1.1 or 2.0. It can generate import scripts for R, SAS, SPSS, Stata, Mathematica Notebook, Berkeley SDA, MS-SQL, MySQL, Oracle, Vertica and HSQLDB.

Asmurex can only read fixed-length field ASCII data files, but can output to both this format and to CSV. It assumes the first field represents the record type as it does, for example, in the Public Use Microdata Samples (PUMS) files published by the US Census Bureau.

Documentation and user support

Peer support for all OpenDataForge tools may be sought from the OpenMetadata Google Group. Commercial support is available for the Professional and Enterprise editions of SledgeHammer.

Various guides are available:

Instructions on using Asmurex are provided on the tool's Web page.


SledgeHammer is a desktop application with a regular graphical user interface. Caelum and Asmurex are command-line tools.

Expertise required

No particular expertise is required to install and use the applications.

Standards compliance

As mentioned above, the tools use mainly ASCII text files for encoding data, whether fixed-length field format, CSV (comma-separated variable) or another delimited format. SledgeHammer supports DDI Codebook and LifeCycle metadata, and Triple-S interchange files. Caelum reads XML and outputs HTML or PDF using XSLT.

Influence and take-up

It is unknown how many users the tool has, but the OpenMetadata Google Group, representing the community built around these and associated tools, had 4 members at the time of writing.

Last reviewed: 
19 November, 2014