Geoscience Reference
In-Depth Information
50 other open source software packages and 15 commercial packages, resulting in
its widespread use and status as a de facto standard for data format in atmospheric
and related sciences. Likewise, the OPeNDAP software, which was originally called
Distributed Ocean Data System, has found wide use outside the core oceanography
data community where it originated. Open source software also increases opportuni-
ties for software reuse, adaptation to different hardware and software environments,
and customization to user needs. The best example, perhaps, is the use of Linux in
a wide range of electronic and computer systems, including videogame consoles,
mobile phones, personal digital assistants, and personal, mainframe computers, and
massively parallel high-performance computing systems. The large-scale availability
of access to the Internet and Internet applications, coupled with widespread use of
Linux in academia and the availability of inexpensive, commodity microprocessors,
and storage devices, has had a democratizing effect on data provision to and access by
the geosciences community. As an example, today over 160 colleges and universities
worldwide are participating in the Unidata Internet data distribution system and they
are receiving, sharing and distributing data, and integrating them into their educa-
tion and research using inexpensive computers and freely-available, Linux-based open
source applications.
The use of open standards models for middleware, a special kind of software be-
tween client and server processes to ensure consistency and interoperability, is par-
ticularly important for developing new data services. For example, an open standards-
based middleware provides opportunities for the provision of a stable, consistent
interface to a wide variety of applications, on a broad set of platforms and enable
their inter-operability. In the process, it decouples data service providers from users,
allowing end users with multiple clients to access the same services. This can accelerate
the migration of data services to new and diverse platforms. Furthermore, it facilitates
the “wrapping” of legacy systems in standard interfaces, giving them the ability to
integrate with other distributed components and systems. Given the demand for stan-
dards-based, open systems that easily integrate, the open source development process
provides a signifi cant advantage over proprietary approaches to software development
and use.
Interfaces based on open standards are by defi nition publicly documented and
based on an explicit or de facto standard. There is evidence that well developed open
standards for data formats are less likely to become quickly obsolete and are more
reliable and stable than proprietary formats. Having access to the fi le format also al-
lows users and developers to create data conversion utilities into other formats. File
formats that use open standards can assist in long-term archiving because they allow
for software and hardware independence. Open standards also allow for greater fl ex-
ibility and easy migration to different systems and interoperability of diverse systems.
Open access, open source software models, and open standards each offer a number of
signifi cant benefi ts in the provision of data services.
The XML, is a simple, highly fl exible, text-based framework for defi ning mark up
languages. This standard for classifying, structuring, and encoding data allows organi-
zations and services to exchange information more easily and effi ciently. Although
