As you may know, Geany is an open-source, lightweight IDE (integrated development environment) built in GTK2, being installable on the most popular desktop environments, due to the fact that it does not require many dependencies.
Among others, it has syntax highlighting features, it auto-closes the XML and HTML tags, has support for C, Java, PHP, HTML, Python, Perl, etc, has code folding features, support for symbol name auto-completion and construct completion and code navigation functions.
The latest version available is Geany 1.33.01 (Unstable – Git Version), which has been released a while ago, coming with changes and new features.
In order to successfully install the latest version version of Geany available, you have to install snapd on your system and to install the geany-gtk package from the edge channel. The bellow commands work on Ubuntu 18.10 Cosmic Cuttlefish, Ubuntu 18.04 Bionic Beaver, Linux Mint, Elementary OS and other Ubuntu derivative systems:
$ sudo apt-get update
$ sudo apt-get install snapd
$ sudo snap install geany-gtk --edge
In order to uninstall geany-gtk, do:
$ sudo apt-get remove geany-gtk