Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.
Pro Exceptionally simple and scalable multithreaded and concurrent programming.
Simply prepend a function with go to execute it concurrently. Utilizes channels for communication between goroutines which aids to prevent races and makes synchronizing threads effortless. The maximum number of threads to use may be defined at compile time, even if that is limiting goroutines to run on one thread.
Pro API documentation is rich in content; easy to memorize.
Only features deemed critical are added to the language to prevent cruft from working it's way into the language. The language is small enough to fit inside one's head without having to repeatedly open documentation. Documentation is hosted on an official webpage in a manner that is simple to read and understand.
Pro The go compiler compiles binaries instantly — as fast as a scripting language interpreter
Compiled binaries are fast — about as fast in C in most cases. Compiles on every OS without effort — truly cross-platform compiler. As a result of the fast compilation speed, you can use the gorun program to use go source code as if it was a scripting language.
Pro Easy to install and configure; simple to compile software.
Go software can be immediately installed, regardless of your operating system, package manager, or processor architecture with the go get command. Software is compiled statically by default so there is no need to worry about software dependencies on the client system. Makefiles and headers are no longer necessary, as the package system automatically resolves dependencies, downloads source code and compiles via a single command: go build.
Pro Demonstrates a unique, simple concept to object-oriented programming.
All types are essentially objects, be they type aliases or structs. The compiler automatically associates types to their methods at compile time. Those methods are automatically associated to all interfaces that match. This allows you to gain the benefits of multiple inheritance without glue code. As a result of the design, classes are rendered obsolete and the resulting style is easy to comprehend.
Pro Supports 'modules' in the form of packages.
Every Go source file contains a package line that indicates which package a file belongs to. If the name of the package is 'main', it indicates that this is a program that will be compiled into a binary. Otherwise, it will recognize that it is a package.
Pro Great language for building networking services
Go was started as a systems language but now it has fully committed in the niche of networking services. This has been a brilliant move by Go because it allows them to capitalize on the immense talent of the Go engineering team (who are in the most part network engineers).
In a world dominated by Java EE and slow scripting language, Go was a breath of fresh air and it continues to be one of the most powerful languages if you want to build networking services.
Pro Syntax for exported code from a package is simplified to be less verbose than other languages.
Any variable, type and function whose name begins with a capital letter will be exported by a project, while all other code remains private. There is no longer a need to signify that a piece of code is 'private' or 'public' manually.
Con Designed to make the programmer expendable
Go was designed for large team projects where many contributors may be incompetent. That Go can still get things done under these conditions is a testament to its utility in this niche. Go's infamously weak abstraction power is thus a feature, not a bug, meant to prevent your teammates from doing too much damage. This also means any team member can be easily replaced by another code monkey at minimum cost. Good for the company, bad for you. The more talented programmers, on the other hand, will be very frustrated by having one hand tied behind their back.
Con Hard to abstract even the simplest notions
Go is famously regarded as very simple. However, this simplicity becomes problematic in time. Programmers who use Go find themselves over and over again writing the same thing from a very low point of view. Domains not already served by libraries that are easy to glue are very difficult to get into.
Con Expects prior familiarity with tooling, "advanced" OS use
A standard step of even installing Go is modifying your path -- a person who's encountering their first language might not even understand. It's hard to escape using Go without familiarity with using build tools, managing and organizing project directories, etc. It's not as simple as Python's "just run the .py file with the interpreter."
Con Performance slowdown because of indirect calls and garbage collection
Practically no meaningful Go application can be written without indirect function calls and garbage collection, these are central to Go's core infrastructure. But these are major impediments to achieving good performance.