Terminal software is enjoying a new generation rather than simply returning from the past. Modern TUIs (Text User Interfaces) and lightweight administration tools can monitor Linux servers, inspect networks, operate Kubernetes clusters, work with containers, investigate logs, browse huge email archives or manage infrastructure services without requiring a heavyweight desktop application. The attraction is particularly clear for sysadmins: most of these tools are fast, script-friendly, work well over SSH and keep control close to the machine where the work is actually happening.
The key open-source terminal tools in 30 seconds
- This selection starts with FlarePurge for Cloudflare cache administration and mboxShell for large MBOX email archives.
- The remaining 20 tools are arranged alphabetically, making the list easier to use as a reference.
- btop, below, bottom, lnav and ncdu cover Linux troubleshooting and observability.
- k9s, lazydocker and dive target Kubernetes and containers, while termshark and bandwhich help with networking.
- Most are open source and can be inspected directly through their GitHub repositories.
The definition of a TUI can become blurry. A classic command-line interface (CLI) receives a command, executes it and returns control to the shell. A TUI remains active, provides panels or navigable views and allows continuous interaction.
Not every tool in this list is strictly a full-screen TUI. FlarePurge, for example, belongs here because it represents the same broader movement towards small, focused tools instead of large administration suites. The selection is therefore intended as a practical toolbox for Linux administrators and developers rather than a taxonomy exercise.
Two newer projects worth watching
1. FlarePurge: managing Cloudflare cache without living in a dashboard
FlarePurge addresses a very specific task: purging the cache of Cloudflare zones without repeatedly opening the Cloudflare dashboard.
The project provides native applications for several platforms and communicates directly with the Cloudflare API using scoped API tokens. According to its documentation, there is no intermediary FlarePurge server handling those credentials or purge requests. It supports multiple Cloudflare accounts, complete cache purges and selective purging by URL or hostname.
That makes it interesting for developers, WordPress administrators, agencies and sysadmins who regularly need to invalidate cached content.
The security model is also worth mentioning. An administration utility does not need a Global API Key merely to purge cache. Using a restricted token with only the permissions required for the task reduces the consequences if that credential is ever compromised.
FlarePurge has separate native implementations with source code published under the MIT licence. This is slightly different from the rest of the list because it is not primarily a terminal interface, but its philosophy fits: take a repetitive infrastructure operation and give it a small, focused interface rather than forcing the administrator into a large control panel.
GitHub repositories and project information are available through the FlarePurge project.
2. mboxShell: browsing huge MBOX archives from a terminal
Email archives are rarely included in sysadmin TUI lists, but mboxShell fills an interesting niche.
The open-source project is written in Rust and designed to open, search and export MBOX archives without loading the complete mailbox into memory. That makes it particularly useful for Gmail backups produced through Google Takeout, Thunderbird archives and mailboxes originating from Unix systems.
Its TUI is built with Ratatui and supports vi-style navigation, different layouts, Gmail labels, conversation threading and advanced searches using fields such as from:, subject:, date:, body: and has:attachment.
It also works as a conventional CLI. Administrators can index mailboxes, search from scripts, export messages, extract attachments or merge several MBOX files with deduplication.
The architecture is particularly relevant for large archives. The project uses streaming I/O with a 1 MB buffer and builds a persistent binary index. Its documentation reports tests with Gmail Takeout files exceeding 50 GB while keeping memory consumption around 500 MB, with subsequent openings taking less than a second once indexed.
It is distributed under the MIT licence and provides binaries for Linux x86-64, ARM64 and RISC-V 64, as well as FreeBSD, macOS and Windows.
The project is also the open-source terminal foundation behind Mbox Viewer, a native Mac and Windows application aimed at users who need the same general approach without working from a shell. Mbox Viewer processes mail locally, supports MBOX and EML, Gmail labels, conversation threads, search and export, and does not require uploading the mailbox to a cloud service. Its free version supports mailboxes up to 1 GB, while Pro removes the size limit and adds capabilities such as damaged-mailbox repair and batch PDF/HTML export.
20 more tools, from A to Z
3. bandwhich: find which process is consuming bandwidth
bandwhich monitors network utilization and associates traffic with processes, connections and remote addresses.
For a sysadmin investigating unexplained traffic, that can be considerably faster than manually correlating information from several networking and process tools.
The project is currently more focused on maintenance than active feature development, something worth considering before making it part of critical operational procedures.
4. below: investigate what happened hours ago
Meta’s below solves one of the biggest weaknesses of conventional system monitors: they are usually excellent at showing what is happening now.
below can also record system state.
Its record, replay and live modes allow administrators to collect resource, process, cgroup and Pressure Stall Information (PSI) data and later navigate through the historical state interactively.
That becomes valuable when a server experienced a problem at 03:00 but looks perfectly normal when someone investigates several hours later.
5. bottom: a modern system monitor written in Rust
bottom, launched using the btm command, provides another modern alternative to top and htop.
It displays CPU, memory, network, storage, sensors and processes through an interactive interface.
There is little reason to install every resource monitor available, but bottom is worth testing alongside btop before choosing a preferred tool.
6. Broot: navigate enormous directory trees
Broot is designed for exploring large directory structures without dumping thousands of filenames onto the screen.
It combines interactive tree navigation with fuzzy searching, file previews, content searches and disk-space analysis.
For application servers containing deeply nested deployments or large source trees, it can replace a surprising number of repetitive combinations of find, tree, grep and du.
7. btop: one screen for the health of a Linux server
btop is one of the easiest modern TUIs to recommend.
It displays CPU utilization, memory, disks, network activity and processes on a single screen. Administrators can filter processes, inspect details and send signals without continually switching between top, free, ps and other utilities.
It is particularly useful as the first command after connecting to an unhealthy server.
8. dive: inspect container images layer by layer
dive addresses a problem that lazydocker does not: understanding what is actually inside a container image.
It visualizes Docker and OCI image layers and helps identify which changes added files or unnecessary weight.
Platform engineers can use it to understand why a supposedly simple container image has become several gigabytes in size.
9. Dolphie: MySQL and MariaDB monitoring
Dolphie brings real-time MySQL and MariaDB monitoring into the terminal.
Rather than acting primarily as a SQL editor, it concentrates on operational visibility, including sessions, queries, replication and database activity.
This makes it especially useful for database administrators troubleshooting a remote server through SSH.
10. fzf: the fuzzy finder that integrates with almost everything
fzf may be the smallest tool on the list with the largest effect on daily terminal use.
It accepts lists and transforms them into interactive fuzzy searches. Files, shell history, processes, Git branches, SSH hosts and command output can all become searchable.
Integrated with Ctrl+R, for example, it turns shell history into something that can be searched instead of repeatedly traversed.
11. gping: ping becomes a graph
gping takes the familiar concept of ping and plots latency inside the terminal.
That simple change makes jitter, temporary latency increases and connectivity changes much easier to identify visually.
It does not replace mtr, traceroute or packet captures, but it provides a useful additional perspective during network troubleshooting.
12. Helix: a modern terminal editor with sensible defaults
Helix offers many of the capabilities expected from a modern development environment while remaining entirely inside the terminal.
Its appeal compared with a heavily customized Neovim installation is that many features are available without first constructing an extensive plugin configuration.
For administrators who occasionally move from configuration editing into actual remote development, it is worth trying.
13. k9s: Kubernetes without typing kubectl all day
kubectl remains essential, but k9s is often faster when investigating a live cluster.
It continuously displays Kubernetes resources and allows administrators to navigate pods, deployments and services, inspect logs and perform common operations without repeatedly constructing long commands.
The two approaches complement each other: CLI commands are excellent for automation and reproducibility, while k9s works particularly well for exploration.
14. lazydocker: Docker operations from a single interface
Container troubleshooting frequently means alternating between docker ps, docker logs, docker stats, docker inspect and docker exec.
lazydocker consolidates much of that workflow.
Containers, images, volumes, logs and statistics become accessible from a navigable terminal interface without constantly copying container IDs between commands.
15. lazygit: Git becomes easier to explore
lazygit provides panels for files, branches, commits and stashes.
Its advantages become especially apparent with operations such as partial staging, interactive rebasing, conflict resolution and cherry-picking.
It does not remove the need to understand Git. It makes operations considerably quicker once the user understands what Git is doing underneath.
16. lazysql: databases from a terminal interface
lazysql applies the same general philosophy to relational databases.
It provides an interactive terminal environment for navigating databases and working with SQL without requiring a full graphical database management application.
That is particularly attractive on remote development machines and environments reached primarily through SSH.
17. lnav: logs deserve an interface too
Log investigation remains one of the most common Linux administration jobs.
lnav, the Logfile Navigator, provides an interactive interface for navigating, filtering and analyzing log files. It can recognize multiple formats and bring different logs together chronologically.
It does not replace centralized logging, but it can make investigation on an individual server considerably faster than repeatedly combining tail, less and grep.
18. ncdu: find where the disk space went
Few Linux messages create urgency as quickly as:
No space left on devicencdu scans directory trees and provides an interactive view sorted by disk consumption.
It is one of those tools administrators often install during an incident and then never remove.
19. Neovim: turn the terminal into a development environment
Neovim can combine syntax highlighting, Language Server Protocol support, autocompletion, diagnostics, fuzzy search, Git integration and a huge plugin ecosystem.
With the right configuration it becomes a complete development environment inside a terminal.
That flexibility also explains its main drawback: configuring Neovim can become a hobby of its own.
20. Posting: API testing without a heavyweight desktop client
Posting is a terminal HTTP client aimed at interactive API development and testing.
It allows developers to construct requests, manage collections and environments and inspect responses while keeping the workflow inside the terminal.
For technical teams, keeping API requests in ordinary files also makes them easier to version and review alongside application code.
21. termshark: Wireshark-style packet inspection in a terminal
termshark provides a terminal interface over tshark, bringing interactive packet analysis to machines where a graphical Wireshark session is inconvenient.
That makes it particularly interesting when investigating traffic directly on remote Linux servers.
It does not eliminate the need to understand capture filters, display filters or protocols. It simply makes navigating captures considerably more comfortable.
22. tmux: remote sessions that survive disconnections
tmux is not a conventional monitoring TUI, but it remains one of the most useful tools for remote Linux administration.
It provides panes, windows and persistent terminal sessions. An administrator can start an upgrade, compilation or investigation, disconnect from SSH and later reattach without losing the running session.
For unreliable connections and long maintenance operations, that capability alone justifies having it available.
Why this generation of terminal tools matters
The common thread running through these projects is not an attempt to turn the clock back to the 1980s.
Most were created because the terminal still has properties that are difficult to reproduce elsewhere.
A Linux server may have no desktop at all. It may sit in a data center, run as a cloud instance, belong to a Kubernetes cluster or only be reachable through VPN and SSH.
A browser-based management interface introduces another service, another authentication layer and potentially another network endpoint. A terminal application usually requires none of those things.
There is also a resource argument. When an administrator connects to a server precisely because memory or CPU is exhausted, adding a heavyweight administration layer to determine the cause makes little sense.
The implementation languages tell another part of the story. Rust, Go and modern C++ appear repeatedly across today’s terminal ecosystem. mboxShell, Yazi, bottom and several other projects are examples of software designed recently by developers who could have built graphical applications but deliberately chose a terminal interface.
The result is also visible in the range of tasks now covered.
A sysadmin can inspect resources with btop, reconstruct a previous incident with below, analyze logs with lnav, find disk consumption with ncdu, inspect packets with termshark, operate Kubernetes with k9s, investigate container images with dive, browse a 50 GB email archive with mboxShell and keep the entire session alive inside tmux.
There is an important security caveat.
Installing every interesting GitHub project on production servers is not good administration. Source provenance, release signatures, dependencies, maintenance activity and required privileges should all be considered.
A packet analyzer may need access to raw network traffic. k9s may inherit credentials capable of modifying an entire Kubernetes cluster. A database client can potentially alter production data. ncdu can delete files. A convenient interface does not make the underlying operation safer.
The best approach is therefore to add these tools when they solve an actual operational problem.
That also explains why the traditional CLI is unlikely to disappear.
Commands remain superior for automation, scripting, documentation and repeatability. TUIs are particularly effective for exploration, investigation and continuous interaction.
Modern Linux administration increasingly uses both.
The terminal has not replaced the graphical desktop, and graphical tools have not replaced the shell. What has changed in 2026 is the quality of the software living between those two worlds.
Frequently asked questions
What is the difference between a CLI and a TUI?
A CLI normally executes a command and returns a result, while a TUI remains active and provides an interactive terminal interface. TUIs are generally better for browsing and investigation; CLI commands remain preferable for automation and scripts.
Which terminal tools are most useful for Linux sysadmins?
btop, below, ncdu, lnav and tmux provide a strong general-purpose starting point. k9s and lazydocker become useful for Kubernetes and containers, while termshark and bandwhich address networking.
What is mboxShell used for?
mboxShell is an open-source Rust application for opening, searching, browsing and exporting large MBOX email archives from the terminal. It is especially useful for Gmail Takeout backups, migrations, audits and mail archives stored on Linux or Unix systems.
Are open-source TUIs safe to install on production Linux servers?
Open source makes the code available for inspection, but that does not automatically make every binary appropriate for production. Administrators should evaluate the source, maintenance status, distribution method and privileges required before installing additional software on sensitive systems.