It doesn't have to be.
Just use your favorite language.

There would be advantages of using your own language (both natural and
programming languages), instead of English and English based
programming languages: it would make your software most costly to
aquire by US corporations, more difficult to spy by the NSA and CIA.

There are network-effect reasons why once the Internet developped, the
use of a common natural language increased. Before that, there were
still isolated research and development centers in most countries that
used their own languages, and even sometimes developped national
programming language (I know of French, Russian, Chinese programming
languages).

But one could consider that nowadays there is a big enough national
programmer community that we could stand a little bit more of
isolation, and therefore use national languages.

In a way, Japan, Korean and China do that. They definitely have
"enough" programmers, and their language is hardly readable outside of
their countries. There's probably a lot of very interesting
eg. robotics papers and programs available from Japan, but since I
don't speak Japanese, I'll never know.

On the other hand, computing and notably programming is still very
divided; there are thousands of programming languages, and apart from
the most "popular" the vast majority of them only have a small
population of programmers working with them. Therefore you still
definitely want to benefit from any network-effect you can have thru
the Internet, and for this reason, you will use almost exclusively
English to publish documentation and sources in those programming
languages.

Using a national language would work only for more popular language.
But it would have to fight the influence of the language providers.
In the privative world, it's the operating system and GUI framework
providers who decide what programming language to use, and while it's
generally possible to use a different language, it's often rather
costly and difficult to do so. So Apple (actually NeXT Computer Inc)
decided on Objective-C, and now Apple is deciding to switch to Swift.
Android decided on Java. Microsoft decided on C++ (and C# and Visual
Basic, but mostly C++ with MSVC). But in terms of national security
and national independence it would be a bad idea to use those american
operating system that contain a lot of privative software. So you
could use GNU/Linux as a base (but Richard Stallman is American and
aimed to clone an American operating system (unix) so of course he
used English and C to write GNU, and for the network effect, Linus
wanted to get help from more than just the Finish programmers, so he
used English and C to write the Linux kernel), and over this free
base, you could develop your own national programming language, with
your own system utilities and non-localized applications. Since this
would be a major enterprise (companies doing that such as Apple,
Microsoft of Google, are "worth" more than most countries), you would
need a strong public support, this would give work to a lot of
national programmers (and you couldn't use alien programmers, no H1B,
since they just wouldn't know the language to read the specifications
and documentation or the programming language to write the programs).

Clearly, this is a project that is antithetic to the internationalist
capitalist point of view. A corporation wouldn't invest in such a
project, because it would have to pay national programmers a higher
salary than hiring cheap immigrants, or off-shoring development to
third world countries. And they wouldn't want to use a language and
programming languages that would restrict their "IPOability" to
international capitalist corporations (that can pay in worthless US
dollars).

Remains that children don't necessarily know English, therefore there
is still place for some programming to be done in a national language
(to teach programming to children and otherwise non-English speakers),
and even for a national programming language, to be used in a
pedagogical context. But if your nation is enslaved in the capitalist
system where people have to be employed by corporations and obtain
money to survive, then eventually they will have to learn a popular
English programming language and work for a corporations that
potentially will be eaten alive by an international capitalist
corporation from the USA (see eg. Microsoft with Nokia, after having
gutted and digested all it could from it, patents, human "resources",
intellectual "property", they're ready to resell the empty
shell. http://www.forbes.com/sites/petercohan/2014/07/18/to-help-bo...
And this is not unique, it occurs constantly. I'd argue that if Nokia
had been more 100% Finish, it would have been much more costly for
Microsoft to acquire it and to exploit it, and possibly Nokia would
have been stayed Finish and these people would have still be able to
develop those nice Nokia smartphones).