Right, "Nasal" is just a weird name for a FlightGear specific scripting language that's based on JavaScript/ECMAScript concepts - as such, someone with a background/familiarity in C/C++ or Java/JavaScript programming should have no problems whatsoever using it - indeed, it could just as well be called "FlightGear C++" if you prefer that (seriously, at the time back in the early 2000s, people wanted to call it FGScript, and Nasal started out as NASL)
Aside from that, there's experimental Python support for extending Flightgear, search the forum/wiki or mailing list for "FGPythonSys" to learn more:
https://wiki.flightgear.org/FGPythonSyshttps://wiki.flightgear.org/Python_in_FlightGearSpeaking in general, "Nasal" itself is rarely the problem when it comes to extending FlightGear - if in doubt, run a forum/wiki or mailing list search about replacing Nasal - discussions about replacing Nasal usually tend to mention keywords like "python", "javascript" or "erlang", so you could just as well run a forum search for all of those:
search.php?st=0&sk=t&sd=d&sr=posts&keywords=Nasal+Python+erlang+Javascripthttps://wiki.flightgear.org/What_is_Nasalhttps://wiki.flightgear.org/Nasal_success_storieshttps://wiki.flightgear.org/Nasal_FAQ#W ... f_Nasal.3FFinally, Nasal "the language" is not complicated at all - if you are familiar with basic programming concepts (conditionals/loops/functions, data structures) you can get going very quickly, just by looking at a few examples/snippets and start adapting those as needed. There's even a built-in console to enter/execute Nasal code directly:
https://wiki.flightgear.org/Nasal_ConsoleAlternatively, try the REPL:
https://wiki.flightgear.org/Interactive_Nasal_REPLwhat you will need to read up on are FlightGear specific APIs (extension functions) and modules/libraries - however, that will be the case regardless of the programming language you are using.
Thanks to features like the generic protocol system, telnet/props, HLA, and most recently DDS, you could also implement addons/features separately, even using visual basic or delphi if you wanted to:
https://wiki.flightgear.org/Generic_protocolhttps://wiki.flightgear.org/Telnet_usagehttps://wiki.flightgear.org/Data_Distri ... es_Supporthttps://wiki.flightgear.org/High-Level_Architecture