TimeSeries.Guru is described as 'A relaxing hosted time series database. TSDB with sophisticated querying, joining and aggregation via HTTP REST API. Storage from 1 GB to Terabytes. On-Demand and Pay-Per-Use. Cloud ready'. There are six alternatives to TimeSeries.Guru, not only websites but also apps for a variety of platforms, including Linux, BSD, Self-Hosted solutions, Python and fontconfig. The best alternative is Graphite, which is both free and Open Source. Other great sites and apps similar to TimeSeries.Guru are KairosDB (Free, Open Source), OpenTSDB (Free, Open Source), Axibase Time Series Database (Free) and Cube (Free, Open Source).
ATSD is purpose-built for analyzing and reporting on massive volumes of time-series data collected at high frequency. Features include data analytics, visualization, data forecasting, reporting, alerting. All in one product built for big data.
Cube is a system for collecting timestamped events and deriving metrics. By collecting events rather than metrics, Cube lets you compute aggregate statistics post hoc. It also enables richer analysis, such as quantiles and histograms of arbitrary event sets.
DalmatinerDB is a metric database written in Erlang. It takes advantage of special properties of metrics to make trade-offs. The goal is to make a store for metric data (time, values) that is fast, has a low overhead, and is easy to query and manage.